Kufstein fortress is one of the most impressive medieval constructions in Tyrol. It is located on a hill rising above the city of Kufstein. This fortress has already been built very early in order to control the entrance from the Alpine foothills into the Inntal valley. However, it has been mentioned for the first time in 1205 AD, when it was in possession of the bishops of Regensburg. In 1415 it was reinforced by Louis VII, Duke of Bavaria.
In 1504 the city and the fortress were besieged and conquered by Emperor Maximilian I. Maximilian had the massive round tower built between 1518 and 1522, substantially adding to its defensibility. From 1703 to 1805 it was a Bavarian possession, returning to Austria in 1814. The fortress acted as prison for a number of political dissidents during the Austro-Hungarian empire.
Today it houses the City Museum of Kufstein. Part of it is also used for concerts and meetings.
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.