It's only a little over an hour from NYC but Storm King it feels like a world away. A lush, alien world with huge unique formations made of heavy metal among other things, dotted throughout the landscape. The park consists of over 500 acres which offer wonderful strolling options and visitors are allowed to picnic in designated areas.
Where else can you see works of Goldsworthy, Calder, and Menashe Kadishman whose Suspended is especially impressive, in a natural environment. Plus this place is pretty trippy, I saw some dudes in flame visors rolling a blunt to experience Storm King's mind blowing environs. They stay open late on most summer weekends.