Osterstein Castle is the former castle of the town of Zwickau, today it houses the nursing home.
First mentioned in 1292, it was badly damaged in a fire in 1403, and demolished between 1404 and 1407 under William I, Margrave of Meissen. It was rebuilt during the reign of Christian I, Elector of Saxony in 1587-1590 as a magnificent Renaissance castle.
In the 18th century Zwickau Prison was established in the castle, which with interruptions, was used until after the Second World War. There were numerous prominent prisoners, including Karl May, August Bebel, Rosa Luxemburg and Martin Hoop.
During the Second World War, it was used as a concentration camp. On 31 December 1962, after 187 years, the use of the castle as a prison ended, although a public bathhouse continued to operate in an intermediate wing of modern construction, on the Dr.-Friedrich-Ring. The former arsenal and the cell block were used to house the archives of the local coal mining industry, and for storage by various local businesses. Parts of the premises were demolished.
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.