In 1189, Count d'Urgell Ermengol VIII donated some land in the Horta d'Avall to build a monastery for nuns of the order of Sant Benet. This site was known as Les Franqueses and the main driving force behind the project was the count's mother, Dolça de Foix.
From the 13th century, an important monastic community was established there with more than fifty nuns, four priests, a deacon and eight serfs. Over time the monastery accumulated an extensive heritage, but due to difficult management and isolation, a period of decline began in the 14th century.
Despite the efforts to reverse the situation, the monastery was forced to be attached to the priory of Poblet, which in 1700 sold it to the nobleman Francesc Portolà, who turned it into an agricultural holding.

Today only the church, some vestiges of the closing wall and the base of the cloister remain of the ancient cenobi.
Santa Maria de les Franqueses is a typical Cistercian construction, with a Latin cross plan covered with a barrel vault in the transept and pointing to the rest of the nave. It has three apses, of which only one is visible on the outside, and chapels in the transept. The windows are arched, and the rose window is double-horned, decorated with geometric and vegetal elements. The interior is quite austere and there is practically no decoration, with the exception of some very stylized elements.
As for the other spaces of the monastery, it is believed that in the cloister area there would also have been the refectory, the chapter house and the library. It is also believed that on an upper floor there would be the rooms of the nuns.