What do you if your city is built around a narrow river and needs a major grade-separated rapid transit line, but for whatever reason you can’t afford a subway? Why, you build a rivertop monorail, of course!

That’s what the city of Wuppertal, Germany did way back in 1897, when it built the Schwebebahn, or “floating train.” It’s been open and running ever since, except for a time during World War II when it was damaged.

Monorails have a fairly limited useful niche. They’re more expensive and less flexible than light rail, and have a more limited capacity than heavy metro rail. Their main advantage over traditional elevated rail is that their structure can be airier-looking, and therefore prettier.

Generally speaking, monorails are only useful if you’re going to build a rail line that you know will be 100% elevated, and if you’re worried a lot about aesthetics. A line running on top of a river is basically the perfect place. Just about anywhere else, you’d build something more traditional.

Anyway, the Schwebebahn is fascinating. Certainly it’s one of the world’s most unique transit lines. Here are a couple of pictures:

Schwebebahn in 1913. Public domain image linked from Wikipedia.

Schwebebahn in 2007. Image from Flickr user Ian Fisher.