In the 13th century, the town of Kadaň was promoted to a 'Royal City'. It began to thrive and a new town was built on the heights above the river, with a castle and Franciscan monastery. The castle was mentioned first time in 1289. It was established as a four-wing Premyslid castle with a housing palace over the river. It served as the seat of the royal burgrave – the administrator of the Kadan region.
The castle was rebuilt in the mid-15th century. After it had been damaged during the Thirty Years Wars, Maria Therese allowed it to be rebuilt as military quarters in 1750. The eastern wing is used for the municipal library with an internet cafe and ceremonial hall. The Josef Liesler Gallery has been in operation since September 2000. A nursing home is situated in another part of the castle.
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.