Wilhelmsburg was built from 1842 to 1849 as the Citadel's reduit. The Citadel comprised work XII of the Wilhelmsburg and works XIII to XVIII of Fort Wilhelm and was the largest of the town-wall fortifications. In contrast to all the other works; the ›Wilhelmsburg‹ had no ramparts and consisted only of four re-inforced bunkers in the three towers. Over the decades, different regiments and units were stationed here.
After the Second World War, the Wilhelmsburg was officially used as a refugee camp, although several citizens of Ulm, whose homes had been bombed or requisitioned, also took shelter here. At any one time, a total of almost 3,000 people lived in the ›Wilhelmsburg‹, which had its own shop, post office and school.
In 1956, the newly formed German army moved in and up until 1970, soldiers were still stationed in the bunkers of the Wilhelmsburg.
Since then, the more than 570 rooms have been empty, apart from a few that have been rented out to companies.
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.