Sasso Corbaro, known as Unterwalden Castle after 1506 and Saint Barbara's Castle after 1818, is about 600 m south-east of town on a rocky hill. Unlike the other two castles Sasso Corbaro is not integrated into the city walls. The first part of the castle was the north-eastern tower which was built in 1478 to close a gap in the defenses of the city. In 1479 a small garrison was moved to the tower. During peacetime the tower was used as a prison, though at least one prisoner escaped in 1494. The walls and south-west tower were added later. The castle was struck by lightning multiple times during the 16th and 17th centuries, and by 1900 was falling into ruins.
The fortress is a 25 by 25 m square with square towers on the north-east and south-west corners. The east wall is 1.8 m thick and other walls are about 1m thick. All the walls have machicolations and swallowtail merlons for defense. The entrance to the courtyard is through the western wall, and contains evidence of a portcullis. The two story buildings on the south and west walls were both living quarters with a gabled roof. The castle chapel is located on the eastern side of the courtyard.
The north-eastern keep currently has four stories, though no records exist of its original height and roof. It was used as a living area when the castle was occupied.
Today, Sasso Corbaro Castle houses the Sala Emma Poglia which is the 'wooden room' built for the Emma family during the 17th century. Originally located in the entrance hall of their home in Olivone in the Blenio Valley, the room was purchased by the Canton of Ticino in 1944 and housed first in Castelgrande before being moved to the Sasso Corbaro in 1989. The room is panelled entirely in walnut and also includes the stüva, stove which provided heating. The stove bears the crest of the Emma family (an eagle and a lion rampant). The museum also houses temporary exhibits. It is open from March until November.
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.