One of our all time favorite Art Museums. Located on the Hudson River in an old Nabisco factory, the museum is open only until dusk since the space is lit entirely by natural daylight. It's worth a wander, especially through the Richard Serra & Louise Bourgeois rooms.
A moderately strenuous (4.6 miles out & back) hike right in Woodstock. Along the trail you'll find hotel ruins and at the top, you can climb the fire tower to see a extraordinary views of the Hudson Valley and Catskill mountains!