Mortemer Abbey was originally built in 1134 on land gifted to the Cistercians by Henry I of England. The stagnant water of the drainage lake, dug out by the monks to dry up the marshy land around the quick running Fouillebroc stream, was called 'dead mere', 'dead pond' - in modern French 'morte mare' - and gave the monastery its name.
The monks constructed what was then one of the largest Cistercian monastery in the world. Over the centuries, the abbey fell into decline and disrepair. It was rebuilt in the 17th Century, but the decline was irreversible and by 1790, when it was dissolved in the course of the French Revolution, only five monks remained.
The 12th century buildings were already more or less derelict by the time of the French Revolution, and subsequent use as a convenient source of cut stone for local construction reduced them to little more than a ruin. Apart from the cloisters, which are relatively intact, there remains only a shell.
The 17th century buildings by contrast are well preserved and open to visitors, with guided tours available most of the year. The abbey site also has a well-maintained 17th century dovecote, which was also used as a gaol house in the 18th and 19th centuries.
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.