San Francisco Bay Area

The San Francisco Bay Area (referred to locally as the Bay Area) is a populous region surrounding the San Francisco, San Pablo and Suisun estuaries in the U.S. state of California. Although the exact boundaries of the region vary depending on the source, the Bay Area is generally accepted to include the nine counties that border the aforementioned estuaries: Alameda, Contra Costa, Marin, Napa, San Francisco, San Mateo, Santa Clara, Solano, and Sonoma. Other sources may exclude parts of or even entire counties, or include neighboring counties such as San Benito, San Joaquin, and Santa Cruz.
Credit: Wikipedia