A brick Georgian Revival mansion crowns the hilltop providing carefully planned vistas in several directions. Georgian Revival dependency buildings were purposefully placed to the northwest to relate to the mansion and the formal landscaping of the hilltop. A dacha of log construction representing Russian Folk architecture was located adjacent to tho mansion in 1945.
The mansion is located at the very highest point of the hill making it the focal point of the carefully planned ensemble of buildings and grounds. Carefully planned vistas from the mansion, overlook the city to the south and the suburb of Cleveland Park to the north. The mansion is approached from Klingle Road over a stone causeway along a long winding driveway with stone retaining walls which culminates in a more formal circular drive directly in front of the main entrance located on the north facade. This serpentine driveway affords a glimpse of the mansion crowning the hill and views into the informal landscaping at the base of the hill including rustic stone bridges and paths just below and to the east of the causeway. At the crest of the hill just prior to arrival at the main entrance of the mansion, the north vista opens out to the hilly meadow and heavily wooded area of mature trees below.
The Causeway (Tregaron), a country house estate designed in 1912 by Charles Adams Platt and located within the Cleveland Park Historic District in Washington D.C., is significant in the fields of architecture arid landscape architecture. It represents the designs of an important American architect and landscape architect, Charles Adams Platt, who was at the peak of his career when he designed his only country house estate in Washington D.C. The estate retains its historic location, design, setting, materials, workmanship, feeling arid association in the buildings and the landscape features so that its integrity is intact.
The Causeway (Tregaron) is also significant because of its association with Joseph Edward Davies and his wife Marjorie Merriweather Post who were the second occupants of the estate beginning in 194.1. While residing at The Causeway (Tregaron) Davies made significant contributions to American history in the field of politics/government during and after World War II. The Dacha, added by the Davies to the property in 1945 is an integral part of the estate. It is significant as a visual reminder of Ambassador Joseph Davies intimate connections with the Soviet Union.
Built 1912 (Charles Adams Platt, architect)
DC Inventory: January 5, 1979
National Register: June 28, 1990