Alt-Schauenburg is a ruined castle in the commune of Frenkendorf. It is located near the border of France and Germany, and little of the castle remains because of geological events.
There were two Schauenburg castles near Frenkendorf, Alt-Schauenburg about 1 km southwest of the village on the top of Chleiflüeli hill and Neu-Schauenburg to the west. Alt-Schauenburg was probably built around 1275 as the seat of a junior branch of the Schauenburg family. The castle was occupied for less than a century. The 1356 Basel earthquake destroyed much of the castle and shortly thereafter the ruins were abandoned. The ruins were gradually buried, until 1949-50 when they were excavated and repaired. In 1976-77 additional construction helped preserve the site.
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.