You have the famous (or infamous) subways of New York, which have been known to provide a place of residence for medium sized dogs (a.k.a., New York subterranean rats with a New York attitude), and you have this: a passageway beneath the streets of lower Manhattan. I think this is a preview of what is to come when the new World Trade Center Transportation Hub is complete.
rutakintome pictures 
Fabulous shot. Does it link between buildings? Or lead to transportation?
Hi Lignum, and thank you. I think it will be part of the new transportation hub in Lower Manhattan, but right now it helps people get around in Lower Manhattan, which is basically one giant construction zone.