Photo by NCinDC.

Built in 1912 by architect Charles Adam Platt for owner James Parmalee, the Causeway (as it was known then) is a 20 acre estate with open fields, woodlands, stone bridges, formal gardens, a pond, and meandering streams in the Cleveland Park neighborhood. Now a part of the Washington International School, the estate hearkens back to when the neighborhood was comprised of farms, summer houses, and isolated suburban estates like the Causeway. The house itself is a three-story, neo-Georgian mansion with a foyer featuring pillars, high ceilings, and an ivory marble floor.

In 1940, former Soviet Union Ambassador Joseph Davies and his wife, Marjorie Merriweather Post, purchased the estate upon their return from the country. They renamed it Tregaron, which is Welsh for village of three wells. So enamored with Russia, they added a dacha, among other Russian features, to the estate.

After Davies’s death in 1958, the estate was left empty for quite some time. Suggestions for use of the estate ranged from the home of the Vice President, the Russian Embassy, a center for the study of international affairs, or a retreat center. In 1980, the Washington International School purchased six of the 20 acres of the estate, and the Tregaron Limited Partnership, purchased the remaining 14 acres. Concerned that the estate’s gardens and historic space would be substantially altered, the Tregaron Conservancy fought to save the land. The estate was listed on the D.C. Preservation League’s Most Endangered Places in 2005. The next year, the school and the Tregaron Conservancy reached an agreement so that 13 acres of the estate is conserved as open green space, managed by Tregaron Conservatory.