Rioseco Abbey

In 1148 the Cistercian Valbuena Abbey, of the filiation of Morimond, founded a daughter house in a small former hermitage in Quintanajuar, in the Páramo de Masa.

In 1171 this new community received as a gift from the heirs of the nobleman Martino Martini de Uizozes the ancient monastery of Rioseco, the previous history of which is unrecorded.

During the Peninsular War, from 1808 to 1809 the French troops stationed in Medina de Pomar appropriated a large part of the monastery's stores and from 1809 until 29 June 1814 the monks were dispossessed.

An impressive spiral staircase is still preserved, the stone walls of the church still stand, and the bóvedas retain some traces of polychromy.

On account of its state of dereliction the monastery features in the Lista roja de patrimonio en peligro ("Red List of Imperilled Buildings"), to which it was added at the instance of the association Hispania Nostra in 2006.