643 Park Ave | Upper East Side
Opens for performances and for the guided tour that must be reserved in advance
The Park Avenue Armory is a gigantic structure you would not believe to be in the middle of the Upper East Side. Resembling a huge train station, it can house art installations most museums could not dream of for lack of a grand space. Its programing varies from theater to classical music, from performance to mega-installations. Do check their website to see if there is something you like going on and if you are interested in architecture, do book their guided tour of the venues and rooms. This is another of those New York hidden treasures.