Gaslamp Museum at the Davis-Horton House

Twelve prefabricated houses arrived from Maine in 1850, shipped in by merchant William Heath Davis. This one survives as the oldest building in downtown San Diego, its rooms having served as a pre-Civil War military barracks, a makeshift county hospital, city founder Alonzo Horton's residence, and reportedly a hideout for a German spy. Self-guided tours move room to room through the Victorian eras the house lived through, and a two-hour walking tour of the Gaslamp Quarter starts here on Thursday afternoons and Saturday mornings.