San Francisco officially the City and County of San Francisco, is the financial, cultural, and transportation center of the San Francisco Bay Area, a region of 7.15 million people which includes San Jose and Oakland. The only consolidated city-county in California, it encompasses a land area of about 46.9 square miles (121 km2) on the northern end of the San Francisco Peninsula, giving it a density of about 17,179 people per square mile (6,632 people per km2). It is the most densely settled large city (population greater than 200,000) in the state of California and the second-most densely populated large city in the United States after New York City. San Francisco is the fourth most populous city in California and the 13th most populous city in the United States, with a population of 805,235 as of the 2010 Census. [Ref:http://en.wikipedia.org/wiki/San_Francisco]

San Francisco ranks fourth in the world, after New York, Moscow and London, in terms of the numbers of billionaires. It has less than 10% of the population of the other three cities. San Francisco is having the largest Chinese community in the world, outside of China.