1st Spanish mission in Calif.; named for St. Didacus of Alcalá, Spain; founded on Presidio Hill on July 16, 1769, by Franciscan missionary Father Junípero Serra; insufficiently supplied; slow to gain Indian following, with over a year passing before a child was baptized; problems may have been caused by its proximity to the presidio and the influence of the soldiers; moved to present site in 1774; rebuilt several times; small part restored in 1931; area is now a public park that includes the Serra Museum and the Serra Cross