Northern California’s commercial and cultural hub is San Francisco, also known as the City and County of San Francisco. With 815,201 inhabitants as of 2021, the city proper is the 17th most populated in the US and the fourth most populous in California. It is the second most densely inhabited significant U.S. city after New York City and the fifth most densely populated U.S. county, trailing only four of the five boroughs of New York City, with a land area of 46.9 square miles (121 square kilometers ). It is located near the tip of the San Francisco Peninsula. As of 2019, San Francisco was ranked first by per capita income (at $133,856) and fifth by aggregate income among the 331 U.S. cities proper with more than 100,000 inhabitants.