The
San Francisco Bay Area, commonly known as the
Bay Area, is a region of California surrounding and including the San Francisco Bay. The Association of Bay Area Governments defines the Bay Area as including the nine counties that border the estuaries of San Francisco Bay, San Pablo Bay, and Suisun Bay: Alameda, Contra Costa, Marin, Napa, San Mateo, Santa Clara, Solano, Sonoma, and San Francisco. Other definitions may be either smaller or larger, and may include neighboring counties which are not officially part of the San Francisco Bay Area, such as the Central Coast counties of Santa Cruz, San Benito, and Monterey, or the Central Valley counties of San Joaquin, Merced, and Stanislaus. The Bay Area is known for its natural beauty, prominent universities, technology companies, and affluence. The Bay Area contains many cities, towns, airports, and associated regional, state, and national parks, connected by a complex multimodal transportation network.