The town of Leopoldov was founded in 1664-1669 as a fortress against the Ottoman Turks on the initiative of Emperor Leopold I (hence the name). It was granted town status in 1669. The fortress has served as a state prison since 1855. During the Communist Czechoslovakia, the Communist government used the prison for holding and liquidating political prisoners, particularly in the 1950s. The conditions were harsh for prisoners, and the prison was one of the most notorious in the former Czechoslovakia. Among the inmates was Gustáv Husák (from 1954 to 1960), who would be later communist president of Czechoslovakia. The prison was modernized and reconstructed in the second half of the 20th century. Before 1989 there were approximately 2,600 inmates in the prison. As of 1990, it was the biggest prison in the present-day Slovakia.
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.