Ruins of a large stone church lend a mysterious and romantic air to California's seventh mission, anchoring the quiet town of San Juan Capistrano. Nicknamed the Jewel of the Missions for its beautiful site and impressive gardens, San Juan Capistrano was founded by Padre Junípero Serra in 1775 and ranked among the most prosperous of California's missions. Both town and mission are renowned for the swallows that arrive here each year on March 19 from their winter nesting grounds in Argentina; their annual return is celebrated with a popular festival, as is their yearly departure in October.Dominating the mission's entrance courtyard, the ruins of the Great Stone Church reveal the size and splendor that made the cross-shaped edifice the grandest in the mission chain before being toppled by an earthquake in 1812. Its 65ft-high roof was topped by seven domes and a bell tower that could be seen from 10mi away. The church's original four bells now hang in a low wall adjacent to the ruins, and the nearby garden shows remnants of original Romanesque arches, door frames and lintels.Three rooms in the west wing of the central courtyard today display items from San Juan Capistrano's history. Occupying the courtyard's east wing is the mission's original chapel (1776). Today known as the Serra Church, it is thought to be the only remaining building in California in which Serra offered Mass. The Baroque reredos from Barcelona, dating from the 17C, was added in 1924.