Saint Josephs day and San Juan Capistrano.

The mission in San juan Capistrano California.
Lars at the Mission several years ago.

The Story of San Juan Capistrano's Mission Swallows
The Swallows of Goya	Credits
The miracle of the "Swallows" of Capistrano takes place each year at the Mission San Juan Capistano, on March 19th, St. Joseph's Day. As the little birds wing their way back to the most famous Mission in California, the village of San Juan Capistrano takes on a fiesta air and the visitors from all parts of the world, and all walks of life, gather in great numbers to witness the "miracle" of the return of the swallows. Each year the "Scout Swallows" precede the main flock by a few days and it seems to be their chief duty to clear the way for the main flock to arrive at the "Old Mission" of Capistrano. With the arrival of early dawn on St. Joseph's Day, the little birds begin to arrive and begin rebuilding their mud nests, which are clinging to the ruins of the old stone church of San Juan Capistrano. The arches of the two story, high vaulted Chapel were left bare and exposed, as the roof collapsed during the earthquake of 1812. This Chapel, said to be the largest and most ornate in any of the missions, now has a more humble destiny--that of housing the birds that St. Francis loved so well. After the summer spent within the sheltered walls of the Old Mission in San Juan Capistrano, the swallows take flight again, and on the Day of San Juan, October 23, they leave after circling the Mission bidding farewell to the "JEWEL OF ALL MISSIONS" San Juan Capistrano, California. More from wikipedia.