On 1-80, 28 miles North East of San Francisco. Dominated by a vast naval shipyard, Vallejo stands beside the junction of the Carquinez Strait and the Napa River, its links with the sea exhaustively – and not particularly interestingly – detailed in the Naval and Historical Museum (http://www.vallejomuseum.org), 734 Marin Street.

Fans of Johnny Cash, who sang about Folsom State Prison’s miserable qualities, may care to pay their respects to the forbidding penitentary, which lies 22 miles east of Sacramento on Placerville Road, between 1-80 and Hwy-50. A more charitable reason to stop is to make a purchase at the prison shop which sells inmates’ handicrafts, the proceeds going to the prisoners.