I was in the city on a research trip last week and to meet with Joe Daly of Summit Video Productions. We will be filming a piece about pocket parks in New York City in the coming weeks. Joe told me he had been by 520 Madison Avenue which displayed a piece of the Berlin wall in its pocket park located on the 53rd Street side of the building just down from Paley Park. We strolled by it after our meeting and it has been moved inside the lobby of the building. One of the guards told Joe it was moved inside to avoid continued wear and tear.
It's still very cool, but the colors pale in the indoor lighting. Go visit at 520 Madison Avenue and 53rd Street. Afterward go about two doors west and you will find the famous Paley Park.
Find this and other park in BEST Pocket Parks of NYC.