Yaddo is a private artists' retreat on a 400-acre estate at the edge of Saratoga Springs. It's been providing residencies to writers, composers, and visual artists since 1900, and the list of people who've worked here amounts to a significant slice of 20th-century American culture. The grounds are not generally open to the public, but the rose gardens and the exterior of the mansion can be visited.
The gardens are laid out in the Italianate style, with formal beds, a pergola walk, and a reflecting pool. They're most spectacular in late June and early July. Even if you're not a literary pilgrim, the setting — a Victorian mansion surrounded by mature gardens on the edge of the forest — is lovely.