Commanding a hilltop and oriented to the south, Oatlands projects authority and also a lightness uncommon for the period. The stucco-covered brick structure was originally constructed by a George Carter, who took years to build it. The original scheme appears to have been derived from Sir William Chambers's Treatise on Civil Architecture (1768 edition), but much of overall form and interior details are Federal. The large main hall has extraordinary moldings, especially the Indianfeathers motif over the doors. The portico, with columns and capitals made by Henry Farnham of New York, was added in 1827. In spite of the date, their slender proportions are those of c. 1800. Oatlands remained in the Carter family until 1897; in the early twentieth century Mr. and Mrs. William Corcoran Eustis of Washington, D.C., purchased the house and began restoration and additions, such as the rear porch (1910). The National Trust for Historic Preservation acquired it in 1965, and many of the furnishings reflect the early twentieth-century glory years of the house as a center for Washington society and politics. To the east is a substantial terraced garden, originally laid out by Carter, with original brick and stone walls. Mrs. Eustis restored the gardens following Carter's scheme and made some additions, such as the stone balustrades, which she drew from Chambers's book. They fell into decay in the 1960s, and the recent restoration follows her scheme. The grounds contain a variety of outbuildings, including a smokehouse, a granary, and a brick greenhouse.
The house was the center of a large estate, to the south of which, along Goose Creek, stood a large mill complex, also built by George Carter. The small village of Oatlands on Virginia 15 has, as a survivor, the Episcopal Church of Our Savior (1878), a simple red brick building. Farther north on Virginia 15 is Mountain Gap School (c. 1880), a one-room schoolhouse now operating as a museum.