Philadelphia was at one time the center of the world (read: America), this was during the early years of world (read: American) civilization. Philadelphia got real big, it built real big stuff. There were more people in Philadelphia then than there are now, there are a number of factors at play here but mostly once industry left Philadelphia so most of its population.
The good news for industrial decay buffs is that Philadelphia is full of rusted, broken-down factories. It looks amazing. It basically is amazing.
In times previous when Philadelphia was full of people they had a few more train lines, train lines that in the 1970s were decommissioned and soon became an urban retreat for homeless people and a walking trail for intrigued Australians.
It seems bonkers to me that there are tunnels large enough to drive a plane through running under the city, and also the above ground tracks, please, pop a few ferns up there, maybe make it safe and you’d have a bona-fide tourist attraction. Philadelphia doesn’t work like that though, they like their disused train lines rusted and busted. I’m grateful Philadelphians didn’t mind me breaking the law and trespassing to enjoy this unique view of the city.
Dig this, at one point the tunnels come out into a police parking lot and I trespassed straight through it. I’m badass.