San Francisco is an ocean.
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 . San Francisco is the fourth-most populous city in California , after Los Angeles , San Diego , and San Jose , and the 13th-most populous city in the United States -- with a census-estimated 2016 population of 870,887 .