The enclosure of the castle of Angers, nearly a kilometer long and punctuated by seventeen towers, was built from 1230, including the imposing hall of the counts and the chapel of Saint-Laud previously built by the counts of Anjou. Its defensive function was reinforced between 1585 and 1592 to meet the requirements of the artillery, with the creation of sloping bastions on the inner sides of the curtain walls surrounding part of the existing buildings and the leveling of the towers at the level of the patrol path.

The work programme, which is due to start in 2008, is part of the general guidelines for the consolidation, restoration and enhancement of the Château d'Angers defined in 1993, during the redevelopment of the Galerie de l'Apocalypse. After the redevelopment of the gallery itself in 1995, the development of its reception areas in 2002-2003 and the securing of the patrol path of the southern enclosure up to the Porte des Champs, this new programme now concerns the restoration of the external elevations of this same southern enclosure, partly located at the rear of the Galerie de l'Apocalypse, from the south-west bastion on the Maine side adjoining the corner tower (tower no. 17) with its summit artillery terrace, up to the eastern tower of the Porte des Champs (tower no. 9). Planned to be carried out in three successive functional phases, each lasting 12 months, it naturally includes the two superimposed interior casemates of the bastion, its intermediate northern terrace at the rear of the 11th century Salle Comtale and also includes the restoration of the remains of the 14th century staircase with the adjoining light well, uncovered by archaeological excavations and that of the western bay of the former Chapelle Saint-Laud immediately to the west of the Galerie de l'Apocalypse.