Update — Spring 2016: All the rails here have been knobbed.
Spot: Two sets of nine stairs, the second of which has thin square handrail. Also an eight stair with a 45-degree handrail going down the middle of it.
Bust — ♦♦♦♦♦: There are “No Skateboarding” signs posted. The building is a huge bust because it is near a lot of embassies. Security will come out in a matter of minutes and make you leave — sometimes with a huge guard dog. The spot is also fenced off at night.
Location: 47th Street, in between 2nd Avenue and 3rd Avenue. Take the, 4, 5, 6 or 7 to 42nd Street-Grand Central, skate east on 42nd Street until you reach 3rd Avenue, make a left, and skate north until you reach 47th Street. Make a right on 47th Street and it is towards the end of the block.
Pictures (Click to Enlarge):