Octagon Museum

The apex of the Federal style of architecture pioneered in the USA also happens to be the oldest museum in America dedicated to architecture and design. Designed by William Thornton (the Capitol’s first architect) in 1800, the building is a symmetrically winged structure designed to fit an odd triangular lot. Behind it, the American Institute of Architects’ (AIA) large modern offices wrap around like a protective older brother. AIA operates Octagon House and the building was closed for renovation as of press time, but should be open by the time you read this; tours ($5 prerenovation) can be arranged by calling ahead.