Introduction of San-Francisco-Bay
Bay, 50 mi long, 3 to 13 mi wide, in N California.Important in the early exploration of this area, thebay was discovered by Sir Francis Drake in 1579,sighted by Gaspar de Portola in 1769, and entered byJuan Manuel Ayala in 1775. Its natural harbor is oneof the finest in the world, now with an underwatertransit tube designed to absorb earthquake tremors.Treasure Island and Alcatraz are well-knownisland s in the bay. San Francisco, Berkeley, Oakland ,and San Mateo are the major cities on itsshores. San Jose is approximately 12 miles to thesoutheast. San Pablo Bay is to the north, leading tothe Napa Valley.