Best contemporary art museum in NY, have to take a train that goes along the Hudson river (best views during fall season!) / rent a car. This museum only uses natural light, and has pieces from Richard Serra, Judd, Sol Lewitt, Walter de Maria, Robert Smithson, Flavin, all best of the best!
Dia:Beacon is a short train ride from the city in a former Nabisco box printing factory. This art foundation has 240,000 square feet of art from the 1960s to the present. Dia features the work of Sol LeWitt, Imi Knoebel, Andy Warhol, Dan Flavin, Agnes Martin, On Kawara, Bruce Nauman, and many others. I love going during the summer to enjoy the gardens surronding the building.
Coming back from from New Haven, we got off at Grand Central and he took me down one of the concourses to the place with the vaulted ceiling. He stood at one corner and I stood at another and we whispered into the walls, our voices drifting across to each other.
An hour away from NYC, there lies a summer camp on a pristine lake which was abandoned 15 years ago. I cant tell you where this is, but some research can lead you to the right place.