John Muir National Historic Site is located in the San Francisco Bay Area, in Martinez, Contra Costa. It preserves the 14-room Italianate Victorian mansion where the naturalist and writer John Muir lived, as well as a nearby 325 acres (132 ha) tract of native oak woodlands and grasslands historically owned by the Muir family. The main site is on the edge of town, in the shadow of State Route 4, also known as the "John Muir Parkway".