Mission San Xavier del Bac, about 10 miles south of Tucson on the San Xavier Indian Reservation, began in 1692 at an older Sobaipuri O’odham settlement known as Wa:k, or “Water Place.” After an earlier church was disrupted by Apache raids and destroyed in 1770, Franciscans built the present church between 1783 and 1797 with O’odham labor under architect Ignacio Gaona. The oldest European structure in Arizona, it is widely regarded as the finest Spanish Colonial mission church in the United States. Despite periods of decline after 1837, it revived under U.S. rule and remains an active Franciscan mission, pilgrimage site, and landmark.