We took the train up to Ossining today and walked a bit on the Old Croton Aqueduct Trail. At the end of the day, we headed to the Croton-Harmon station by foot: it was warm, but the views sure were beautiful.
day trips from NYC
Magnum opus
Looking for a quick day trip? Opus 40, a large-scale sculpture built on an old bluestone quarry outside of Saugerties (about two hours from NYC), was created by Harvey Fite over a span of 37 years. The Times wrote about it here, if you're interested.