The ruins of the guesthouse are among the best preserved in the abbey. Built at the end of the 13th century, this monumental building nearly 40 metres long and 12 metres wide, could accommodate some hundred guests, including poor people and pilgrims. The refectory room was punctuated by cross vaults supported by columns and surmounted by a comfortable dormitory upstairs. The large fireplace was used to warm the guests and to cook the food from the kitchen.
In the 16th century, the building was converted into a brewery. Beer was produced by fermenting barley grains stored on the first floor.