Octagon Hall sits about five miles north of downtown Franklin, set back from US 31W in a stand of trees. It is one of the only eight-sided brick houses ever built in Kentucky and one of a handful in the United States. The design — popularised by phrenologist and amateur architect Orson Squire Fowler — was supposed to admit more light and air than a conventional square plan. In practice it created some genuinely peculiar interior spaces, which is part of the appeal.
The Civil War history is what most visitors come for. Confederate troops camped on the grounds during the war and the house briefly served as a hospital. The Octagon Hall Museum operates the property as a historic site with period furnishings, military artefacts, and a reputation among ghost hunters that it does not particularly discourage. Open Saturdays for tours and by appointment.