The strategic importance of the mountain crest across from Ehrenberg has been known for a long time. In 1632 the Swedes marched to the gates of Ehrenberg. Only years later, from 1639 to 1645, under the Tyrolean regent Archduchess Claudia Fort Claudia was built, and named after this princess. In 1703 Fort Claudia was taken by the Bavarians, who began the occupation of Ehrenberg from here. In 1782 the fortress was closed down. Even in the 19th century, the old fortress was inhabited, yet was left to decay after it was abandoned.
In 2014, the world's longest pedestrian suspension bridge was completed between the Ehrenberg Castle ruins and Fort Claudia, spanning the strategically important pass that these two structures were in part meant to guard. The length of the bridge 403 meters, with a height 110 meters.
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.