This research library, museum and gardens sits on the highest point in Georgetown. It's on a beautiful residential street and is definitely worth a look if you're in the area. The museum (admission is free) specializes in Byzantine and Pre-Colombian scholarship, art and artifacts, and the gardens are spectacular.
The original 1801 mansion was bought and renovated by philanthropists Robert and Mildred Bliss in the early twenties. They later donated the house, gardens and collections to Harvard University in 1940. Cameras weren't allowed in the museum, but I also toured the gardens. The gardens were designed by Beatrix Farrand in 1921 as a complex series of outdoor rooms and terraces planned to take advantage of the hillside setting. It has a 'forgotten paradise' kind of feel with quirky stonework and sculpture laid out along irregular brick pathways that meander in all directions. The entertaining terrace just outside the back end of the house was designed using only green foliage so that blooming plants wouldn't compete with the colorful women's evening dresses! Here is a virtual map and tour... I don't think I saw half of it, and I was exhausted!
The last 3 photos are from the Dumbarton Oaks website
Sue/the view from great island