Engelbourg Castle was built around 1224 by Count Frederick II of Ferette to guard the entrance to Thur Valley. It was severely damaged a few centuries later during the Thirty Years' War and destroyed on the orders of Louis XIV in 1673, when its strategic role was no longer valid.
The main tower broke into several sections.The main part fell on its side looking towards the town of Thann, and this is what we call the Witch's Eye, as it seems to stare at the roofs in the village and off into the horizon.
Today, it can be reached by a steep stairway in about 20 minutes or by a walk through the vineyards in about 40 minutes. It is worth making the effort as you will have a magnificent panorama over the valley, the collegiate church and the town of Thann.
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.