Built on a promontory near the top of the Georgetown Hill, the Dumbarton Oaks Research Library and Collection consists of a museum, library, various auxiliary buildings, and spectacular gardens that step down the hillside into the Rock Creek Valley to the north. Originally a large farmhouse, the property was first transformed into a private estate by Mildred Barnes and Robert Woods Bliss before its gift to Harvard University and subsequent transformation into a research institution. Dumbarton Oaks' famed gardens, designed by the American landscape architect Beatrix Farrand, negotiate the steep grade in a series of rooms that cascade down the hillside.
This idyllic setting occupies an important place proximate to the District's water infrastructure: the Washington City Tunnel, serving the McMillan Reservoir, runs directly under the grounds. Additionally, had the plans to convert Rock Creek Valley into a reservoir prevailed, the vista toward the Kalorama neighborhood would have been decisively different.