San Juan Capistrano, a small city (1990 pop., 26,183) in southwestern California, is located 81 km (50 miles) southeast of Los Angeles between the Santa Ana Mountains in the east and the Pacific Coast on the west. Founded in 1776, it grew up as a farming community around the Spanish mission of the same name, which honors St. John of Capistrano (1385–1456), an Italian theologian and crusader. The mission of San Juan Capistrano, constructed in 1797–1806, was badly damaged by an earthquake in 1812; its adobe Serra Chapel (named for the mission founder Father Junípero Serra) is the oldest building in California and is presently being used by clergy of the Los Angeles diocese.

An unusual phenomenon at the mission was first recorded in 1777. Every year, on St. Joseph's Day (March 19), swallows arrive there, having flown 9,700 km (6,000 miles) from Goya, Argentina, to nest and rear their young; they leave again on October 23. The arrival of the swallows is celebrated by the Fiesta de las Golondrinas. Tourism is a principal mainstay of the town. The old Santa Fe Railroad Station (1895) has been restored and serves as an Amtrak station.