You can see this in SF Mission and the old Southern Pacific lines, and why some blocks are so oddly shaped, and why there are parks that have the strangest configurations. Out of place diagonal lots, parks, roads. Very hard to erase those legacy shapes.
Similarly, seeing long stretches of green or empty space and realizing that there's a giant water pipe underneath stretching from the Sierras, and that's why there will never be a house built on that <xyz> lot.
(Funny, and I never seem to find among my friends anyone else who takes interest in it.)
I find this fascinating, too. I'm in western Ohio near an abandoned line that connected Indianapolis, IN to Springfield, OH. The line is still very apparent in satellite photos nearly 50 years after the last bits were retired. Likewise, in the property records, the "scar" the line left on the land is clearly visible.
In a few places landowners purchased the parcels on both sides of the line and "reconnected" them, but mostly the line's legacy is a bunch of oddly-shaped property lines cutting across a grid of 80 or 160 acre fields. In those "reconnected" places it's interesting to see how the crops and soil have a slightly different appearance (or not-so-slight, in some cases).
Many of the little towns along the line have a "Railroad Street", too. The town I grew up in did, but I'm old enough to remember when the abandoned rails were still there.
Similar to the railroads leaving their mark, a few years ago I got a bit obsessed with the Hetch Hetchy aqueduct. I spent a few evenings laying in bed "flying" the line with Google Earth, seeing where the pipes diverge and following their separate paths, and seeing where they meet up again. Seeing how San Jose and Palo Alto are situated on top of the line is interesting. I'm resolved to visit the Pulgas Water Temple and any public spaces I can walk on top of Hetch Hetchy next time I'm in the Bay area.
I always get a little sad when I go looking for things like this. Today it costs a billion dollars per mile to build rapid transit, and yet there are cities where they just tore up their rapid transit system. My favorite is probably a branch off the Green Line in Chicago. You can start here: https://www.google.com/maps/@41.8220133,-87.6169737,3a,60y,2... and zoom out and follow the entire route. A transit desert with lots of space for development, that way because the rapid transit route got torn up. (Info about this particular line: https://www.chicago-l.org/operations/lines/kenwood.html There are a lot of them in Chicago.)
Much of the system dates from the same era and handles 2000s era passenger loads. But yes, deferred maintenance has its cost; a coat of paint prevents the superstructure from rusting away, once that paint is gone and the superstructure has rusted, then it has to be replaced entirely.
That was the sticking point for this particular branch. It needed money in an era where trains were boring and the glorious automobile was our savior, so wasn't going to get any money. It turned out that was not the best long term solution, and that's the sad part. People were onto something with this whole "streetcar suburb" and dense ubran rapid transit system. But, it hit some rough patches, and here we are today. (Overrun by cars and their pollution, but without a transit system that would let people get rid of their car.)
There's a stretch of disused railway near here which is still clearly visible in aerial photos over 170 years after it was closed... (https://en.m.wikipedia.org/wiki/Newmarket_and_Chesterford_Ra... -- the line from Six Mile Bottom to Chesterford closed in 1851. This is about where it diverged from the still-existent Cambridge-Newmarket line:
https://maps.app.goo.gl/qXRZ84sd97A5gK4Q8 -- if you turn on the satellite-image view it's easy to see curving off to the south.)
I came in here to say as much. I even had a railroad spike I found from a (pre-?) Civil War era railroad line when I was 13 or 14, but my mom threw it away at the time because it was "junk".
I was out for a walk in Kirkland (across the lake from Seattle) the other week and found a little paved path that ran about 1/4 mile through a wooded area. I could tell by the amount of engineering they would have had to do to raise the grade that it wasn't just some 50s foot path. So when I got home, I looked at the King County Parcel Viewer (Google it if you live around here, it's worth it) with the 1936 aerial photo basemap...and couldn't find it. Some more digging revealed that it was a railroad built in the late 19th century to service the Great Western Iron and Steel Company, which was partially built but never finished. So even to all the people looking up and pointing at that airplane in 1936, the railroad was still something only their grandparents would have seen being built.
There's a shelf in a hill nearby in the woods. I eventually found out it is the remains of a "skid road" used to clear the logs out when the old growth was all logged out.
Sometimes you can find a gigantic tree stump here and there.
I've always enjoyed the weird odd lots and the parks that fit in some of them in the Mission. Still hoping that eventually something gets done with the one by the Atlas Stair building [1]. I've also always wondered why Treat doesn't seem to line up with the rest of the line farther south, and this site says that it's because a small rail yard was there [2], which makes it look like Treat was a siding and the main line ran down Harrison.
Fun fact: this was also the line that used to take bodies to the cemeteries in Colma, which is why there are still a couple mortuaries around, e.g. the one right off 17th and Valencia amidst all the fancy restaurants, and apparently a working crematorium at 17th and Folsom?
When I was in New York for a week 15 years ago, I bought this book https://forgotten-ny.com/book/ and had real fun walking around to spot all the places in the book. Not sure how many survive still…
I used to visit Utsubo Park in Osaka. Walking the long corridor with the dividing hedge, it was easy to envision the airstrip it once was. But it isn't so obvious to me from aerial photos.
That's an interesting question. The area north of Potrero didn't become residential until quite recently and I don't think they ran streetcars in the specific place I'm thinking of. They were basically tracks in an industrial part of town headed in the direction of Southern Pacific rail.
Seattle has abandoned railways that could be re-used for light rail at minimal cost (they actually sit there with rusting tracks on them). Instead, every effort has been made to destroy those corridors, so that tens of billions of dollars can be blown by blasting new corridors for light rail.
funny example, bellevue is the atherton of seattle. they caused such a stink during planning of the line 2 extension microsoft, boeing and t-mobile sent the city council a letter telling them to shut the hell up
I could never get the Seattle Times to ask questions about why the Eastside Rail Corridor, running from Renton to Bothell along I405, could not be used. Their journalism about it looked like press releases from the government.
Though I have gotten hate mail calling me an uninformed idiot to imagine that railroad tracks paralleling the most congested freeway in the state could be used for light rail. No, it must be destroyed.
This isn't the only track the county has destroyed. There's the line from Renton to Black Diamond that was used to stuff a mattress, and one paralleling Bothell Way that was used as a beehive.
Most of the old railways on the Eastside aren't suitable for new development because they're surrounded by low density suburbs. Any stations built along a new line would have very little traffic, making the whole system kind of pointless, unless it was designed as a high speed system. But doing that wouldn't be able to use the existing lines anyhow because they have too many curves.
All I can say is, nice try. I live here. It parallels I405 which moves at a walking pace for most of the day. All those people are going somewhere - and Kirkland, Bellevue, Renton are all major destinations. Have you looked at the skyline of Bellevue lately? The corridor goes right by it. Around the north and south ends of Lake Washington it could connect to the rest of the light rail, making a complete circuit around the Lake which divides the metropolitan area in half.
Really, what could be more useful? I'd use it all the time. Sure, it wouldn't go by my house, but I'd drive to the station and take it for the major part of my trip.
It doesn't have to be high speed. It just has to be faster than the gridlocked I405 with a predictable schedule. I always have to leave an extra hour early to drive to the airport because I might get stuck on I405 for an hour.
I live here too. Maybe we can meet some time and have a chat? There's a huge stretch of the old line running up through Kirkland which is pretty much completely surrounded by houses. One option to make it more useful would require building more car parks, but that's not a terribly good option.
The one section through Bellevue as shown does run along I-405, but on the wrong side with respect to downtown. So any trip along I-90 to downtown and beyond would take longer. There's a small stretch of the old line which did get repurposed at NE 8th street, but the old rail couldn't be kept anyhow because it wasn't elevated.
There's also the problem that the old rail is just one set of tracks, and so another set would be needed anyhow. Of source the original set would need to be replaced due to age. And there's the Wilburton trestle, which would have to be ditched and replaced for pretty much the same reasons.
The nice thing about the system that we're getting is that it connects to the new regions of the city which have higher urban density, like the Spring District. Keeping a few sections of the old line would result in slower travel times, and I don't see much savings in terms of cost.
If light rail were put up on it, the value of the adjoining real estate would suddenly go way up and the density would appear.
Yes, it's on the "wrong" side of 405 from the downtown area. About a 10 minute walk (I've done it). Oh, the agony :-) But it's on the "right" side if you want to go to the hospital, or Whole Foods, or any of the other businesses there.
> There's also the problem that the old rail is just one set of tracks, and so another set would be needed anyhow.
Not necessarily. With modern technology, one set can service both directions safely. I'm also sure adding a track will cost <<< less than adding a new right of way and a new road bed and two tracks.
> Of source the original set would need to be replaced due to age.
I'm sure that replacing a set of tracks is far less costly than blasting a new right of way, making a road bed, and putting new tracks on it.
> And there's the Wilburton trestle, which would have to be ditched and replaced for pretty much the same reasons.
Or it could be - maintained.
Another person said it couldn't be done because a station would have to be added here and there at incredible cost. Of course, the only thing a station actually needs is a slab of raised concrete. I tend to be amazed at the monumental structures Seattle Transit likes to build as stations.
> If light rail were put up on it, the value of the adjoining real estate would suddenly go way up and the density would appear.
That would require rezoning low density residential areas, which is practically impossible.
> About a 10 minute walk (I've done it). Oh, the agony :-)
I've done it too. For a pedestrian, 8th street is a complete hellscape. How many people working/living in downtown would enjoy adding 10*2 minutes of hell each day to their commute?
> With modern technology, one set can service both directions safely.
How often is this done? If this would save costs, then all the new lines should be doing this, but I don't see it happening anywhere.
> Or it could be - maintained.
Bridges have a finite lifespan, and the trestle is almost 120 years old. It won't last forever, even if maintained.
> That would require rezoning low density residential areas
If they can blast new right of way through it, they can rezone it.
> For a pedestrian, 8th street is a complete hellscape
I agree. I recommend 10th instead.
> How often is this done?
Beats me. With modern tech, how hard can it be? It'll work up to a certain level of traffic, then a second track will be needed, and it'll be obvious and the funds will be easier to get.
> Bridges
It only has to last long enough to prove the need. And light rail, being light, is not going to stress it. The thing was built for heavy freight traffic.
>>> There's also the problem that the old rail is just one set of tracks, and so another set would be needed anyhow.
>> How often is this done?
> Beats me. With modern tech, how hard can it be?
All that's need is a handful of passing loops and modern signalling. It's how we in Scotland got the railway from Edinburgh to Tweedbank re-opened (part of the old Waverley route from Edinburgh to Carlisle that was closed during the Beeching cuts).
They demolished the crossing of I90 just south of the trestle in Bellevue. And now it looks like they're putting in a pedestrian bridge to replace it. I'm not sure why they had to remove the tunnel in the first place. I used to cross it and hang out over the southbound lanes with friends.
The Kirkland section of the trail actually gets a fair amount of use as a bike and walking route and connects sections of Kirkland that weren't easy to connect before. With the South Kirkland park and ride to at the south border I know a few people who used it to bike to the bus system.
Kemper Freeman I think has a lot to do with why the train line wasn't used for light rail.
That's the problem with turning it into a bike path. Sure, it's nice to have a bike path. But a bike path moves maybe 1% of the commuters that light rail would.
A bike path minimizes utility, rather than maximizes it.
I've really started to enjoy biking "rail to trail" lines in Kansas. The Flint Hills Trail is 115 miles of biking, relatively no elevation change... but the best part is absolutely 0 motorized vehicle traffic, making it quite enjoyable.
If you ever get a chance to bike it I would, and consider making a donation to the foundation that builds these out.
If you’re relatively close and interested in a long rail trails, I’d recommend checking out the Katy Trail next door in Missouri. It’s the longest rail trail in the US.
I wanted to call bs on this, but for now it seems you are right. In Texas, there are plans to take an abandoned railroad line from about Farmersville to a location fairly close to Texarkana. I am not sure the exact mileage, but I would think it must compete. Here is an off the cusp link about it.
It only manages to pull off this designation because the route from Pittsburgh to DC is technically 2 rail-trails (there's a tiny road segment of less than a mile that connects them in Cumberland, MD). Either way, the more rail-trails the better!
One of the rails to trails routes here in Virginia that I've ridden my bike on features a pretty large and relatively high bridge that spans acroases a river and much of the woods surrounding it. The more narrow bridge makes it easier to see over both sides like a typical pedestrian bridge but having that experience in the middle of the woods and above the trees was rather magical.
I'm not sure I'd characterize that particular trail as "no traffic" [1]. Large segments of the route you describe are along country roads where you share the road with cars and trucks traveling at 55mph. As much as I wish it weren't so! That'd be so much fun. :)
Perhaps you're thinking of the Erie canal trail (Buffalo to Albany), which is composed of a much higher proportion of bike trails?
Not at all! I use a "gravel bike", which is sort of made for this kind of stuff (slightly relaxed road riding position, more aggressive weight balance towards rear, wide tires, beefier frame, plenty hardpoints for water). A road bike would suffice with wide enough tires (probably at least 38mm). The surface is mostly packed pea gravel, but there is some clay dirt streches and some spots that are "Kansas Road" grade... meaning chipped/rutted chert/limestone.
A mountain bike would certainly work but is overkill. The upright riding position of a mountain bike catches a lot of wind and you'll expend a lot of calories/water inefficiently, and they're not made for low rolling resistance.
Awesome - I have an old 80s touring frame that I have completely revamped with lighter 29er wheels and 35C touring tires (usually works pretty well on gravel), wide dirt drops, full racks, etc etc. Brooks saddle of course. Probably would work great for that (although maybe even wider tires would be better - bike has cantilever brakes so I can go pretty wide if I wanted)
Very interesting site, although not all the rail routes listed are actually abandoned per se. For example, I live next to a popular and well-maintained trail that used to be a railway, and the site still lists it as an abandoned rail line.
Abandoned for rail use though. If you are hiking somewhere like the allegeny national forest, these abandoned rail routes are a boon since they are generally raised up out of mucky ground, flat, and easy to navigate along if you know which one you are on. Hunters frequently just walk along the abandoned railways when searching for game. Why not call it a trail at that point? IMO because this isn't built like a trail (which can have complicated terrain or scrambles up or down some steep terrain), its built like a railway, and should be marked as such on a map since that will tell you a lot about the conditions on that route (raised, flat, generally free of obstructions short of fallen trees since abandonment)
Usually rail trails are deliberately constructed and maintained however. Although the degree to which this is done varies. And it's also not uncommon for some section of a rail trail to have been worked on and other sections are in the plans for someday--whether because of money or local opposition.
ADDED: And as noted elsewhere the railroad or its successors in ownership often still own the right-of-way--however unlikely it would be to revert a popular rail trail to rail use.
Rail trails weren't created just by being left to rot, they had to be legally abandoned by the railroad before they could be converted into trails (in the US, anyway).
One of the reasons rail trails are fairly popular is because it preserves the railroad right-of-way for potential future use. Even if the rails are removed and pavement put down, it's far cheaper to pull the pavement up and re-lay rails if you need the line in future (like for light-rail or commuter service) rather than to have to re-acquire the right of way again or build an entirely new line. The term is "railbanking." [0]
This actually can become a problem in the future. Here in Montgomery County, Maryland there was an old rail line converted to a bike path but always with the intention of adding light rail to a portion of it.
20 years later, they started the project and the local cycling groups are upset because their path has to be split and rerouted in places to support the new line. Delayed the thing many years as a result.
I noticed the same for my local area. The site listed an abandoned rail that has long since been turned into a popular paved bike path. The pictures for the rail even show the bike path instead of rail.
The large Vermont line this site returns was a causeway across lake champlain which is an active enough bike path that there is a seasonal ferry service for the portion of the line that used to be a bridge. Whether there are tracks there or not these still leave visible scars across neighborhoods.
I remember I used to go to this old railroad bridge and hang out and fish, there were signs of life there, bb gun marks on the metal, graffiti, beer bottles. I wasn't the only one spending time in this space.
It made me think about how we think of infrastructure as animals. When we think of a road, we think of it in much the same way we think of a forest or a river. It's just there, a permanent part of the landscape. But these things must be maintained, and all of it will be ruins one day. Every single thing we have built will lose it's purpose, and eventually it's form. And in much the same way you see things like wasps and pigeons moving into unused structures, humans will do the same in our own human way.
Saw the posting and wondered if the site listed any of the many abandoned lines I see here in Montana. Turns out it does: https://www.abandonedrails.com/montana
I'm particularly fascinated with the Homestake Pass line, which is easily visible from the adjacent I-90 freeway -- you can see the rails are still in place. Apparently it was never actually closed, they just never ran another train after some date in the 1980s. Subsequently there have been some tunnel collapses that make the line unusable.
I sometimes question how such items come to be posted on HN as many of the non-tech posts here I share great interest in and this topic is no exception.
I live next to one of these abandoned railroads, one of the earliest in the country actually, which Daniel Boone wrote about riding along with many U.S. Presidents as well as Kings and Queens of foreign countries. The items I have recovered from surface hunting and metal detecting this area have been eye opening from many aspects. The U.S. National Archives has the blueprints of the design for this railroad I live next to digitized and available online and many years ago I studied it out of curiosity for the value of understanding the history of my area. What I could not have known at that time of studying was that a few weeks later I would discover pieces from the construction that matched the U.S. National Archive designs to a T - I was stunned. I have also since come to learn these pieces are in great demand from avid railroad collectors but I just do it for the lulz and not the money. Through my 10 years of researching and exploring historical information in my area I would share with everyone that if you live near a historical location and have interest in the past do your research first.
As a serial entrepreneur my point for the HN community is that opportunity is everywhere and in studying history one can discover exactly where to look for such opportunity. This logic applies to nearly everything.
we do a terrible job of corridor preservation in the states. lots of converting old rail right of ways to trails or redeveloping them. the utility of simply leaving them empty, especially in urban areas, is hard to overstate.
probably the example in the bay is the dumbarton line, which has been preserved and in a world where CAHSR wasn't politically compromised would be the route off of the caltrain towards the altamont pass. the altamont alignment is technically superior to the chosen pacheco alignment on all metrics (cost, speed, operational constraints), but pacheco was chosen due to lobbying by san jose politicians, who, suffering from a massive inferiority complex, demanded that podunk san jose's diridon intergalactic was on the main line and not served by a branch. that decision, btw, pretty much single-handedly compromises the utility of CAHSR. it severely constraints the tph into SF, makes the SF-sacramento trip uncompetitive, and adds billions in unnecessary infrastructure costs
another example is the vasona branch, which branches off the caltrain right of way around cal ave, and slated to be used for a BART line to los gatos during the early days of BARTs development.
>lots of converting old rail right of ways to trails or redeveloping them
Once you make a decision that you don't want something any longer you can't just keep it in stasis forever just in case. As others have mentioned, in many cases, rails converted to trails do maintain railroad right of ways against a future change of heart. Of course, in practice, converting a well-used rail trail back to rail of some sort would be deservedly unpopular in most cases.
There is some great potential for the land these old rails occupied if they are still owned by the rail company but no longer have tracks. Some of the spaces in urban/city areas are probably not the most desirable places, but others can (and have been) transformed into interesting spaces.
A great California Bay Area example is the REAP Center in Alameda. It's on a half mile of old rail line easement that's now what you might call an Urban Farm Makerspace, though those that make it happen would describe it much more eloquently.
I've stayed there a number of times when visiting, and it's this wonderfully peaceful place where you feel like you're away from the city, but are close to the estuary with Jack London Square basically in sight.
If you're ever wanting to see what an old rail line space can turn into, go check it out. It's anything but an "abandoned rail line".
My favourite part about https://www.openrailwaymap.org/ is that it shows abandoned and razed tracks, although you have to zoom in somewhat. I wonder if there is a way to make it highlight those tracks at a higher zoom level.
Here's one in Austin - it's pretty cool to see how other infrastructure has used it's Right of Way, including the Southern Walnut Creek Trail, electrical transmission lines, and other roads - https://www.abandonedrails.com/georgetown-to-pershing
Note: this is next to another rail line that is still in use. I think the commentors on the site discuss that, but I don't quite understand what they are saying.
Edit: looking at this further - the Right of Way is nearly intact for most of it's original length. It would be so cool to have a bike trail for this entire thing.
Some routes were taken from rancher via eminent domain or similar. Basically forced easement onto private property. Some of those easements no long exist with the rail routes being abandoned.
Can confirm. My family used to own a chunk of land that had part of an abandoned rail line on it (the rail and ties themselves were gone, but the path was very obvious) and the map shows some near it, but not that one.
It engendered lots of 'ghost train' campfire stories. And they installed a lot of infrastructure to support it, including highway overpasses and crossings - there are still a couple now-purposeless overpasses on Highway 69 that once crossed it.
There are plenty of abandoned railways in Canada, none of which seem to be available on this site. The claim of "in North America" is BS. The creator would be better off just saying "in the United States" considering that North America includes Canada, Mexico, and Greenland.
They have Felton to the Boardwalk run in Santa Cruz county as abandoned but Roaring camp bought it and runs tourist trains on that route. Weekends all year and everyday during the summer...
Edit: Searched the site and found it. Looks like the Felton to Campbell is the abandoned part. Not that you would know it from their main map...
There was an abandoned railway near my house when I was growing up. I used to go for nature walks there and see wildflowers, hummingbirds, butterflies, etc.
To the way it once was, never. In many places, these glory days had a train on the tracks a couple times a day in each direction and that was attractive. People were happy sleeping on trains and the time taken to travel was usually less than the alternative of steam boats, dirt roads, or horseback.
Even in the best case of NYC where much of its rail infrastructure stayed active, and the area population soared, subway ridership hasn’t bounced back to 1946.
It's already happeneing. Many of us associate car ownership with immaturity, captivity, and a general sense of being annoying to oneself and others.
Each morning, during my bike commute, I see thousands of car-drivers stuck inside their cages, stopped in traffic, and I feel sad for these poor people; and at the same time annoyed for the enormous space they take, the noise they make, the pollution, and how ugly their absurd machines are.
For anyone in the San Francisco Peninsula and South Bay area, here are a few that may be of interest.
Foothill Expressway was originally a train line. If you know where the old Fry's Electronics was in Palo Alto, the line branched off from the main Southern Pacific line near there, went by the loading docks behind the buildings where Fry's was - it was a major cannery at the time - went through what is now Bol Park, and turned onto Foothill where the VA hospital is now.
Foothill makes a bend to the right at Homestead, but the train line continued straight through at that point, going through what is now the Trader Joe's parking lot. If you notice a diagonal NW-SE path through the parking lot that continues onto Homestead Ct and Peninsular Ave, that was the railroad alignment.
Highway 280 wasn't there at the time, of course, so the line continued straight through to the still-existing Union Pacific line that serves the Kaiser Permanente quarry, and then down to the line that parallels Winchester Blvd in Campbell. This right-of-way currently has three tracks on it: northbound and southbound light rail lines, and the Union Pacific line.
I used to live in an apartment that overlooked this railway, and it was great fun to hear and see the Union Pacific freight train that comes through twice a week. Just like at Fry's, you can see several of the loading docks in the buildings in downtown Campbell.
On the east side of that line, there was a branch that went south to serve the New Almaden mines. If you ever wondered where Camden Ave in San Jose got its name, it wasn't from the city in New Jersey. This line was called the Campbell-Almaden line, so CAMpbell-almaDEN is where the street name came from.
If you drive Camden Ave from Campbell, you may notice an oddly gentle right turn at the junction with Hillsdale Ave. This turn was gentle for the trains. Farther south, Camden takes a slight right at Clovis, just before Blossom Hill, and there is a powerline right of way that continues in a straight line where the railroad was. The tracks then crossed Guadalupe Creek and followed what is now Redmond Avenue, then turned south toward New Almaden.
Back to Palo Alto, if you know of Hawthorne Avenue, three blocks northwest of University, that was a train line too! Lytton and Emerson were streets at the time, but Hawthorne was a spur line that served the Catholic University in Menlo Park (now St. Patrick's Seminary). It branched off the main Southern Pacific line by the water tower, followed Hawthorne and then made a bend to the left onto what is now Middlefield, then a gentle right into the University. It split into two tracks on each side of the main building.
If you are interested in this stuff, I highly recommend the USGS topographic maps. They have the complete historical maps all online!
Not going to lie, before I visited the site, I was hoping it was a hot take article about why Ruby on Rails now suck and people should stop using it and migrate off of it. I was ready for the comment section.
Sorry. I was submitting it to see if anyone would suggest a way to buy the abandoned tracks to start a commuter service since HN has had so many cargo vs person rail stories lately.
Ruby would have been a bit too hot a submission for me.
Yes, where I live in the greater Boston area, you've seen a few commuter rail extensions that I assume made use of existing railroad right of ways that were abandoned (ADDED: As in no longer used for rail service) at some point once the rail service became commuter rail service
#/media/File:High_Bridge_(35794593764).jpg){kind=link}
You can see this in SF Mission and the old Southern Pacific lines, and why some blocks are so oddly shaped, and why there are parks that have the strangest configurations. Out of place diagonal lots, parks, roads. Very hard to erase those legacy shapes.
Similarly, seeing long stretches of green or empty space and realizing that there's a giant water pipe underneath stretching from the Sierras, and that's why there will never be a house built on that <xyz> lot.
(Funny, and I never seem to find among my friends anyone else who takes interest in it.)