St. Andreas Castle is a privately owned castle located in Cham, in the Canton of Zug. The castle hill has been used since at least 400 AD, based on Roman artifacts found there. The site of the neighboring chapel has been used for religious ceremonies since the Roman era. During the 8th century the chapel site was used by a 'holy bishop without a name' for Christian services.
Today the castle and chapel are located on a 67,000 square metres private park. While the castle is privately owned, the grounds are opened to the public twice a year.
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.