Alt-Signau castle was the ancestral home of the Barons of Signau. The family was first mentioned in 1130 when Werner von Signau appeared in a historical record. The castle was designed to protect and control the road between the Emmental and the Aare river. In the mid-14th century the castle was abandoned when the family moved to Neu-Signau Castle on a hill across the valley.
The ruin is relatively well preserved.
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.