The Ear of Dionysius is an artificial limestone cave carved out of the Temenites hill in the city of Syracuse, on the island of Sicily in Italy. Its name comes from its similarity in shape to the human ear.
The Ear of Dionysius was most likely formed out of an old limestone quarry. It is 23 metres high and extends 65 metres back into the cliff. Horizontally, it bends in an approximate "S" shape, vertically it is tapered at the top like a teardrop. Because of its shape the Ear has extremely good acoustics, making even a small sound resonate throughout the cave.
This cave was dug in Greek/Roman times as a water storage for the 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 and causing damage, and the cave became unusable for water storage afterwards.