The famous double set ledge and all the other ledges here have been efficiently skatestopped, making the more popular obstacles at the spot obsolete. Otherwise, you'll find the overly long three-flat-two double set, which has about seven feet of flat in between the steps. The runway is about a block long, and perfect granite (you'll need all of it). In back, there are two sets of steps, one after another. The first is a six, and the next a seven, both have rather high, yet mellow fat round rails going down them. There's about seven feet of space in between the two sets.
The security window is closer to the rails than towards the double-set. During the day, they'll be quick to spot you, so chances are, you'll get the boot pretty soon. It's best to skate it at night.
46th Street in between Lexington and Park Avenue. Take the 4, 5, 6 or 7 to 42nd Street-Grand Central, skate north on Lexington for three blocks, make a left on 46th and skate up the block. The spot is right before Park Avenue.