This Romanesque church is a UNESCO-listed site as part of the Camino de Santiago. Its assorted decoration contributes to the overall sense of harmony. Inside, the elaborately decorated chancel is surrounded by an ambulatory opening onto four radiant chapels. The lighting subtly brings out the details on the capitals, many highly expressive. Beneath the chancel, the "Souterraine" contains a small Black Madonna, which attracts crowds of visitors every year.