Vallejo ( /vəleɪoʊ/ or /vəleɪhoʊ/; Spanish: [baʎexo]) is the largest city in Solano County, California, United States. The population was 115,942 at the 2010 census. It is located in the San Francisco Bay Area on the northeastern shore of San Pablo Bay. Vallejo is named for General Mariano Guadalupe Vallejo.
Vallejo is home to the Six Flags Discovery Kingdom theme park (formerly Marine World and Marine World Africa USA) ; the now-defunct Mare Island Naval Shipyard; the regional office for Region 5 of the United States Forest Service; the California Maritime Academy (part of the California State University system); the Vallejo Center campus of Solano Community College; and Touro University, an osteopathic medical college. Ferry service runs from a terminal on Mare Island Strait to San Francisco, through Vallejo Transit's BayLink division.
Vallejo has twice served as the capital of the state of California: once in 1852 and again in 1853, both periods being brief. Some of the first Europeans drawn to the Vallejo area were attracted by the sulfur springs; in the year 1902 the area was named Blue Rock Springs. In 2008, Vallejo became the largest California city ever to file for bankruptcy.