Here's a little guide to orient you if you find yourself in Manhattan without a map.
If you're lost in Central Park: Follow a path. Almost all the paths will lead to the Loop, a 6-mile drive that has foot, bike, skating, and sometimes car traffic on it. It traces an imperfect oval inside the park boundaries: from nearly any point, you're only a short ways from the outside of the park. The lampposts, if you look closely, have small metal signs on them which tell you the cross street at your latitude: "100-2" is the 2nd lamp on the Loop above 100th Street; "67-4" is the 4th lamp above 67th.
If you're lost looking for an address: Addresses project east and west from Fifth Avenue: 20 West 43rd Street (the old home of the New Yorker magazine) is in the block between 5th and 6th Avenues. Westward, the first block is 0-99, the second is 100-199, and so on. ...