Monastery of San Miguel de las Dueñas Monument · Congosto, El Bierzo, León The monastery of San Miguel de las Dueñas, a women's community founded between 970 and 980 by Count Gonzalo Bermúdez, a favourite of Ramiro III of León, gave rise to the town of the same name, on the banks of the Boeza river between Bembibre and Ponferrada. Its Benedictine nuns later adopted the Cistercian rule, and since its founding in the 10th century the building has undergone successive alterations that have given it a mixture of styles, with an austere conventual Baroque of the 17th and 18th centuries predominating. It was declared Bien de Interés Cultural (Spain's highest level of heritage protection) on 4 June 1992. Photo: Zarateman (Public domain) What to see and do in Congosto