The mint-green paint job in the Octagon dining room is historically accurate.

Must-see Federal just off New York Avenue! Fully renovated in 1990s! This circa 1801, three-story + basement, red-brick charmer has seven BRs, 13 fireplaces, HUGE formal dining room, drawing room, study! Basement features rustic servants’ hall and housekeeper’s room, perfect for conversion to mother-in-law suite! Kitchen w/ charcoal-powered stove. Unique geometry is a real conversation-starter! W/ two secret doors, hidden staircase. Sunny pastel designer paint job! Desk where Treaty of Ghent was signed, ending War of 1812, does not convey. Plus — ghosts!

The self-guided tour of this historic home, with its sparsely furnished rooms and dearth of museum-y placards, feels one Realtor short of an open house. The American Institute of Architects has no plans to sell, though, so tough luck. Designed by William Thornton (one of the architects of the U.S. Capitol), the Octagon was built to show off the wealth of one John Tayloe III, and it succeeded. James and Dolley Madison found it sufficiently posh to live in after the White House burned in 1814.

The home’s peculiarities start in the entry hall, which gives the Octagon its name: Though the room is round, there are eight angled walls beneath the smooth plaster. The oddest touch is the extra steps at the top of the imposing open stairwell. Thornton added them so, from below, it would appear that the house had four stories instead of three. The Octagon is also, allegedly, the most haunted building in D.C.

Octagon Museum, 1799 New York Ave. NW; free self-guided tours Thu.-Sat., 1-4 p.m., private guided tours by appointment, $5-$10; 202-626-7439.
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