The bricks used to construct the mansion were made on site, and the predominant feature of the structure is the octagonal room in the center of the building. The octagon room stood two stories high, and was meant to support an octagon dome, which was never constructed.
The mansion burned down on Christmas Day, 1884. After the fire, the family renovated the neighboring villa and moved in, leaving the ruins standing.
The mansion is on the US National register of Historic Places, and today it sits in the middle of Barboursville Vineyards. Like the Barbours did over 200 years ago, you can stay overnight at the vineyards in a room at the 1804 Inn (the villa turned bed & breakfast). The winery has named their flagship wine after the heart of this colonial home. Barboursville "Octagon" is a Bordeaux-style blend that is perhaps meant to drink a bit like the wines Jefferson may have brought back with him from France, or like the wines he wished to have made locally in Virginia, but failed to produce because he could not stabilize the viticulture.
Barboursville Vineyards website.
Loving, Boyce. (1955) "Ruins of Gov. Barbour’s Home Still Standing After 71 Years." The Daily Progress. Virginia: Charlottesville. 15 September 1955.
Wilson, Richard Guy. ed. (2002) Buildings of Virginia: Tidewater and Piedmont. New York: Oxford University Press. p130.