Beacon, NY makes for a very solid day trip from pretty much anywhere in the tri-state area. From our house, it was about an hour drive. There’s also a Metro North stop right in town. The main reason to go to Beacon (besides strolling its quaint downtown area) is Dia: Beacon, a beautiful contemporary art museum overlooking the Hudson River. The museum is made up of fairly large spaces and it contains a bunch of fairly large scale pieces - factors that make Dia: Beacon a fairly appealing place for child sized guests, at least as far as art museums go.