The 13th-century Romanesque Iglesia de San Miguel sports an unusual, octagonal cupola–bell tower that reveals Mudéjar influences and a lovely circular apse. Inside is a bas-relief depicting the killing of Thomas á Becket at the hands of the British king Henry II. The work was commissioned by Henry's daughter, Eleanor of Aquitaine, the wife of Alfonso VIII.
The painting has been interpreted as a gesture of penance on behalf of her father.