The legendary Ear of Dionysius is the most famous cave in Syracuse. It’s called this way for its ear shape and above all for its remarkable acoustic properties which amplify the sounds inside it. Its name was given by the painter Michelangelo da Caravaggio. According to the legend, the tyrant Dionysus used it as a jail and he used to eavesdrop on the prisoners’ conversations.
This cave was dug in Greek/Roman times as a water storage for Syracuse. A narrow tunnel was dug first. This tunnel was widened by digging down and sideways afterwards, giving the cave its unusual shape. The small narrow tunnel is still visible on the top of this artificial cave. An earthquake struck this area causing damage, and the cave became unusable for water storage afterwards.
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.