Travel to the United Nations building, which is on the east side and slightly northeast above Grand Central Station. Stand on one end of the flagpoles so that you are facing them in a long row in front of you. Take one step back if you are standing next to them, then charge a jump and land on the first one. Use standard jumps and only press the Analog-stick Forward. With some luck, you should land about four or five flagpoles from the first one. Repeat this about four times. After passing the final flagpole, you will unlock the achievement.