San Francisco is the City and County of San Francisco, in California. San Francisco is located on the West Coast of the United States at the north end of the San Francisco Peninsula. In the United States it is the 16th most populous city, and in California the fourth most populous city. The Alcatraz, Treasure Island and Yerba Buena Island are part of this city, besides small portions of Alameda Island, Red Rock Island, and Angel Island. More than 50 hills are there in the city limits. The tallest hill of San Francisco is Mount Davidson which stands 928 feet (283 m) tall. It covers an area of about 46.89 square miles (121.4 km2). San Francisco was founded on June 29, 1776 and was incorporated on April 15, 1850.