It is located in the old Assumpció Romanesque church (12th century), attached to the abbatial palace, and was built between the 16th and 17th centuries. Since 2001 it has exhibited the Colecció d'Art Sacre de la Ribagorça.
This collection brings together displays of several artistic disciplines, from painting to sculpture, altarpieces, and silver and goldsmithing. There are religious pieces from different historical periods, in particular those falling between the 17th and 18th centuries and Baroque in style (as is part of the architecture of the building, add-ons to the original structure), although there are also pieces from previous periods, the oldest being the Santa Maria del Cóll llosa (tile) from the 12th century.
Of special interest is the set of altarpieces, stemming from small area churches and the church's own collections, conceived as a way to bring various events from the history of religion closer to the faithful.