A two-storey brick building from 1895 that served as the headquarters of the Durant-Dort Carriage Company, briefly the largest carriage maker in the United States. The office is a National Historic Landmark because of what happened inside it — this is, more than any other single spot, where General Motors began.
Owned and maintained by GM as a museum, the building's two floors of restored Victorian offices include period furniture, ledgers, photographs and patents. Admission is free; check hours, which are limited.