The Great Tower Neuwerk is the most significant building of the Neuwerk island, belonging to Hamburg. This former beacon, watchtower and lighthouse is also the oldest building in Hamburg and oldest secular building on the German coast.
The construction was started in 1300. It was completed after ten years in 1310. The style matches the common norman tower type of the time. Contrary to some literature, the tower was built in this form from the beginning. The fire in the 1360s destroyed most of the wooden elements and it had to undergo major reconstruction.
The original roof was made of lead, and was replaced by copper in 1474. This was again replaced in 1558 by a tiled roof and by a new copper roof following that. The copper was then used for military purposes in 1916 reconstructed later.
The original purpose was to host troops to defend the ships entering and leaving the Elbe from sea and beach pirates. The tower was also refuge for the farmers on the island during storm surges and survivors of shipwrecks over the centuries.
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.