Apart from Dia Beacon, in Beacon (upstate New York about an hour away from Grand Central Station) and also the Judd Foundation in Soho, this institution is absolutely one of my favourite places to visit and it is located in Long Island City, Queens. It showcases sculpture in the broadest sense and has an incredible building that used to be a workshop that refurbished and fixed subway cars. It has been running since 1928 and when you visit you will definitely see why that is.
I have old friends in San Francisco who grudgingly tell me that the High Line is everything that's wrong with New York. Well, too bad. To me, it embodies a culture that's constantly reinventing itself: a defunct elevated railway that was becoming a burden to the city ("we used to climb up there to throw garbage bags full of rotting Korean food at the Hasids!", noted a successful photographer's assistant) becoming a startling example of urban greening for the public good. The expert landscaping makes it feel like walking on a Montauk beach - but a stone's throw from some of New York's most progressive galleries and hotels.