About a one hour’s drive north of NYC, up the beautiful Hudson River, is Kykuit. This mansion was built by the oil baron, John D. Rockefeller in 1913. The interior of the house is beautiful and the grounds are spectacular. The nearby town of Sleepy Hollow, NY is also very lovely. It is full of cute shops and cafes for a nice lunch.
The house is now part of the National Trust for Historic Preservation. It is in fantastic condition, and the grounds are extremely well maintained. You must buy a ticket to tour, and it is wise to book in advance. The website is https://www.hudsonvalley.org/historic-sites/kykuit.
Tours run from May through November. As you can tell from the photos, we went in May, and it was so beautiful!
After our tour, we ate at the beautiful Blue Hill at Stone Barns. This is a fantastic farm to table restaurant. The grounds here are great to explore as well. This made for a perfect day. If you want to extend your day even further, there are other mansions nearby which are also open for tours.
I absolutely recommend getting out of NYC and heading up the Hudson River for a look around, if you have the time!