American Folk Art Museum, 45 W. 53rd St.
Asia Society and Museum, 725 Park Avenue (at 70th Street)
Guggenheim Museum, 1071 Fifth Avenue (at 89th St.) Pictured left
International Center of Photography, 1133 Avenue of the Americas at 43rd Street
The Metropolitan Museum of Art, 1000 Fifth Avenue
NEW: Beginning May 1, 2013 MoMA will be open seven days a week. 11 W. 53rd St.
The Morgan Library & Museum, 225 Madison Avenue at 36th Street
Museum of the City of New York, 1220 Fifth Avenue
New York University, Grey Art Gallery, 100 Washington Square East
Mondays and Tuesdays are the hardest days to remember which museums are open. See the list for NY museums open on Mondays here.