18. Mission San Xavier del Bac (Arizona)
Founded in 1692, Mission San Xavier del Bac stands as a breathtaking example of Spanish colonial and baroque architecture in the American Southwest. Located near Tucson, its dazzling white façade, ornate interiors, and vibrant frescoes make it a true architectural gem. Still an active parish, the mission serves as a spiritual and cultural anchor for the region, much like the historic missions of New Mexico and Texas, drawing visitors from around the world.
