It dates back to the 10th century; the original Visigothic establishment joined the Cluny Order under the aegis of Alfonso VI from 1060 to 1075. Its foundation has been established as having occurred during the reign of Alfonso III the Great (866-910). The church has three naves with a transept and three apses separated by cruciform pillars without columns, and the doorway is Romanesque. The oldest part is that of the gable end entrance and the rectangular turret which still survive, although the capitals recall Frómista and Silos. It is inhabited by the well known Trappist monks of Palencia and is 13 kilometres from that city, very near the confluence of the Rivers Carrión and Pisuerga. During mass the Gregorian chant can be heard.