The abbey stands on the foundations of a first church, built in stone, single nave. The construction covered half a century, from 1105 to 1160. The amazing architectural hyphenation, which distinguishes the choir slender most of the nave collected, and reflects the diversity of origin of the contractors. The choir and transept, inspiration ligérienne, attach to a angoumoise nave. Remaniée several times over the ages, it is particularly in 1504 and resumed in the same style as the flamboyant gable top-dormitory during which makes it (behind the kitchens Romance). During this work, the abbess fact hide the door by a Romanesque portal Greek style and Tuscan order, consisting of two pillars, an entablature and a pediment. In the early twentieth century, the architect Lucien Magne restores the Romanesque door that we see today. The nave is supported by pillars and massive square, flanked by twin columns on three sides. Along the walls stretch of blind arches supporting galleries of movement. The dome mounted on pendants, and forming file, delineates four spans. In the north wall (left looking choir) opens the door so-called ""papal"" she gave passing thought to be at Pope Calixtus II 2 came in November 1119, devoting the building still unfinished and confirm the statutes of the Order founded by Robert of Arbrissel. It accesses the transept crossing a few degrees. High slender columns surmounted by twin capitals are soberly decorated with sheets of water. The choir is stripped of any ornamentation: nudity of the columns that surround the ambulatory still exalts in the verticality. Three radiating chapels open in the bottom of the apse. In the nineteenth century, the nave is shared by the prison administration into four levels of stores and dormitories, with its attendant damage to windows and doors. It is the architect Lucien Magne that we must complete the restoration of the abbey in 1906, including the reconstruction of the cupola.