Gudsberga Abbey (Gudsberga Kloster) was a Cistercian abbey established in 1486. It was the last Cistercian abbey in Sweden. Gudsberga owned farms, manors, foundries and mines until 1527, when it was reduced to the Crown during Reformation. In 1538 and 1544 King Gustav Vasa ordered to send silver from abbey to Stockholm. It was demolished later. Today some stone foundations remain and there is a museum exhibiting the forge of abbey.
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.