The Abbey of La Clarté-Dieu was a Cistercian monastery. The abbey was founded in 1239 by the executors of Peter des Roches, Bishop of Winchester, as one of a pair, the other being Netley Abbey in Hampshire, England. The bishop had conceived the idea of founding a pair of monasteries some years before and had begun collecting the necessary endowments for them, but his death in 1238 prevented him from completing the project. The first monks arrived at the site in 1240.
The abbey was severely damaged in the course of the Hundred Years War and the cost of rebuilding proved a heavy burden on the finances of the community. Nevertheless, La Clarté-Dieu managed to survive until the French Revolution when it was closed and sold off along with all the other monasteries of France. Following the revolution the abbey was for a long time used as a farm and some of the buildings were allowed to fall to ruin. Despite this, much of the mediaeval abbey remains in excellent condition along with some fine post-mediaeval additions. The abbey is preserved as an historic monument and is open to the public.
References:The Walls of Constantinople are a series of defensive stone walls that have surrounded and protected the city of Constantinople (today Istanbul) since its founding as the new capital of the Roman Empire by Constantine the Great. With numerous additions and modifications during their history, they were the last great fortification system of antiquity, and one of the most complex and elaborate systems ever built. They were also the largest and strongest fortification in both the ancient and medieval world.
Initially built by Constantine the Great, the walls surrounded the new city on all sides, protecting it against attack from both sea and land. As the city grew, the famous double line of the Theodosian Walls was built in the 5th century. Although the other sections of the walls were less elaborate, they were, when well-manned, almost impregnable for any medieval besieger.