California contains San Francisco.
The 1906 San Francisco earthquake struck the coast of Northern California at 5:12 a.m. on April 18 with an estimated moment magnitude of 7.8 and a maximum Mercalli intensity of XI ( Extreme ) . San Francisco . Located at the north end of the San Francisco Peninsula , San Francisco is about 47.9 sqmi in area , making it the smallest county -- and the only consolidated city-county -- within the state of California . After three-quarters of the city was destroyed by the 1906 earthquake and fire , San Francisco was quickly rebuilt , hosting the Panama-Pacific International Exposition nine years later . The San Francisco Bay Area ( referred to locally as the Bay Area ) is a populous region surrounding the San Francisco and San Pablo estuaries in Northern California .