Contra Costa County’s most famous landmark is Mount Diablo, with its 3,849-foot peak visible countywide on a clear day. The County seat is in Martinez. Contra Costa County is proud of its distinguished schools, parks and services to its communities. The popular Contra Costa County Fair is held annually in Antioch. There are many spectacular natural attractions, such as Briones Regional Park, with panoramic views of the valley, the Sacramento Delta and River, all the way to Mount Tamalpais in Marin County, and Las Trampas Regional Wilderness. Visit the John Muir Natural Historic Site and tour the Victorian home of the famous preservationist. The Martinez Historical Society houses a comprehensive Contra Costa County history library. Those who prefer shopping and dining will not be disappointed either.