The early medieval church of la Asunción Monument · San Vicente del Valle, Montes de Oca, Burgos In the early Middle Ages it was the monastery of Santa María del Valle. The building, perhaps of late Roman origin, was transformed into a church around the year 900 and preserves paired windows with horseshoe arches on columns with capital and impost. Photo: Luis Rogelio HM (CC BY-SA 2.0) What to see and do in San Vicente del Valle