A remarkable village since the times of Fernán González, it grew under the protection of the monastery of San Salvador and the grace of the monarchs. In addition to the arch of Estrella, the fortified walls, and the church of San Juan, the visitor should not miss the church of San Salvador, which still has some Romanesque windows, and a Gothic-Mudejar arch. The interior is richly ornamented, specially the royal pantheon, where lie the remains of Sancho el Mayor of Navarre and Sancho García. A historic play called "El Cronicón de Oña" is staged there in the summer. The cloister (16th century) was made by Juan de Colonia.