Tunnel vision: how an obsessed explorer found and lost the world's oldest subway | The Verge
- f you went on one of Diamondâ€™s tours, which ran between 1982 and 2010, you could see why the FDNY was concerned. Heâ€™d lug three plastic orange barricades out to the middle of Atlantic Avenue, pry off the manhole cover with a crowbar, and steady a thin ladder into the narrow shaft, the only entrance to the tunnel. Tourists would line up in the middle of the busy road, descending one by one into a tight passageway. It led to an Alice in Wonderland-sized doorway that opened up on a large staircase, built by Diamond and his colleagues in the â€˜80s. The stairs lead down into a massive, spooky hall that is 2,570 feet long, 21 feet wide, and 17 feet tall.