It's nice up on the old Reading Viaduct.
It's exactly like the High Line in NY, except no one maintains it, so it isn't the lamest place on Earth.
(There's been talks for years about making it a park up there, but I really hope it never happens. Call me a hipster.)
You get quite a view of the city, and there's always someone interesting up there. Drugs and crime never get too bad, since the surrounding apartment tenants walk their dogs up there all the time.
They come and go with weather/vandalism, but people hang swings from the those metal posts.
Don't have a ton of pictures, but if you skip to around 0:50 in this vid, you can get a feeling:
https://www.youtube.com/watch?v=OK6QwjLfBIM 