Back during the 1970's when I was twixt 18 and 20 I used to love to explore Grand Central Terminal. I used to love to see where different stairways, tunnels, and pathways led. I remember getting a beautiful view of the main terminal from up near the ceiling when I discovered the walkways that ran in between the huge windows. I allways had a deep admiration and fascination with Grand Central.

Then there are a lot of oddities. Like the hole in the ceiling that was made in 1957 in order to enable a Redstone missile to be put on display in the main terminal concourse.

A few more oddities here

http://www.amny.com/urbanite-1.81203...inal-1.1382517