Built by oil tycoon John D Rockefeller as his summer home and completed in 1913, this 40-room mansion is listed on the National Register and has lovely grounds landscaped by Frederick Law Olmsted. On display as sculptures around the estate and in an underground art gallery is a remarkable collection of modern art including works by Picasso, Chagall and Warhol.
Admission is only by tour, which depart from Philipsburg Manor; hours vary. A shuttle bus will take you out to the estate from here. Tickets are $2 cheaper if bought online.