Bay Area, California

The San Francisco Bay Area, commonly known as the Bay Area, is a populated region that surrounds the San Francisco and San Pablo estuaries in Northern California, United States. The region encompasses the major cities and metropolitan areas of San Francisco, Oakland, and San Jose along with smaller urban and rural areas. The Bay Area's nine counties are Alameda, Contra Costa, Marin, Napa, San Francisco, San Mateo, Santa Clara, Solano, and Sonoma. Home to approximately 7.44 million people, the nine-county Bay Area contains many cities, towns, airports, and associated regional, state, and national parks, connected by a network of roads, highways, railroads, bridges, tunnels and commuter rail. The combined urban area of the region is the second-largest in California (after the Greater Los Angeles area), the fifth-largest in the United States, and the 56th-largest urban area in the world.