A really cool video shot by Charles le Grand who described the tunnel:
Under Manhattan’s Upper West side, runs the “Freedom” Tunnel. Built in the 30’s by Robert Moses, the passage boasts legendary graffiti murals and piles of debris remaining of the past homeless city era. After using it for only a couple of years, Amtrak discontinued the line and left a massive cavern which later became a shelter for street people. Progressively, the tunnel turned into a veritable underground metropolis where thousands of homeless were living in organized communities underneath the city’s skin.
Freedom Tunnel from Charles le Brigand on Vimeo.