San Francisco, officially the City and County of San Francisco, is the cultural, commercial, and financial center of Northern California and the only consolidated city-county in California. San Francisco encompasses a land area of about 46.9 square miles on the northern end of the San Francisco Peninsula. It has a density of about 18,187 people per square mile , making it the most densely settled large city in the state of California and the second-most densely populated major city in the United States after New York City. San Francisco is the fourth-most populous city in California, after Los Angeles, San Diego and San Jose, and the 14th-most populous city in the United States—with a Census-estimated 2014 population of 852,469. The city and its surrounding areas are known as the San Francisco Bay Area, which is a part of the larger OMB designated San Jose-San Francisco-Oakland combined statistical area, the fifth most populous in the nation with an estimated population of 8.6 million.
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