Part historical house,  and part art museum, Kykuit stands apart from other historical homes and is hands down the top attraction in Sleepy Hollow. With an amazing collection of works from modern artists (Warhol, Picasso, Miro, Calder, Brancusi, Betancue, etc) you should visit just for the art. Sadly this is not an art museum but a historical home and all this must be appreciated as you walk through with little time for careful study. Stunning architecture and views of the landscape throughout, though visitors are NOT given free access to the grounds. Still there is a sense of exploration as you are walked through a home that still looks like it was lived in. More updated than other historical homes, the home does not feel ostentatious and actually integrates well with its environment. 

Visitors are driven up from a separate location, and note there is a bit of walking. (Elevators are available for those that need but limits somewhat your tour) Bathrooms are limited, (end of tour in carriage house) no food options other than what's at the initial visitor center, though there are places in nearby Sleepy Hollow. Expect limited cell service.  Lots of great picture opportunities, nearby Irving home and Mill are much smaller. Note it sometimes closes for the season.