The Great Tower Neuwerk was completed in 1310 as a defensive tower and later served as a lighthouse for ships entering the Elbe. It is the island's dominant building and, because Neuwerk belongs to Hamburg, the oldest surviving building in the city-state.
The tower has been used as a watchtower, beacon, refuge during storm surges, and lookout over the Wadden Sea. Even when access changes during restoration work, it remains the island's essential landmark.