San Xavier del Bac
This historic Catholic mission was founded in 1692 by Padre Eusebio Kino on an old Indian settlement. This is the oldest European structure in Arizona built between 1783-1797. It is considered to be the finest example of Spanish Colonial architecture in the United States. Being a pilgrimage sight, more than 200,000 visitors come to the mission each year on horseback (called "cabalgatas" in Spanish).