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later during the Thirty Years' War and destroyed on the orders of Louis XIV in 1673, when its strategic role was no longer valid.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 ancient Argos Theater was built in 320 BC. and is located in Argos, Greece against Larissa Hill. Nearby from this site is Agora, Roman Odeon, and the Baths of Argos. The theater is one of the largest architectural developments in Greece and was renovated in ca 120 AD.
The Hellenistic theater at Argos is cut into the hillside of the Larisa, with 90 steps up a steep incline, forming a narrow rectilinear cavea. Among the largest theaters in Greece, it held about 20,000 spectators and is divided by two landings into three horizontal sections. Staircases further divide the cavea into four cunei, corresponding to the tribes of Argos A high wall was erected to prevent unauthorized access into the theatron and may have helped the acoustics, but it is said the sound quality is still very good today.
Around 120 CE, both theaters were renovated in the Roman style.