The Ear of Dionysus is an artificial, funnel-shaped cave, carved into the limestone, about 23 m. high and 5 to 11 m. wide, with a singular shape, vaguely resembling an ear pavilion, that develops 65 m. deep, with an unusual S-shaped course and sinuous walls that converge at the top, in a singular acute arch. The cave is, moreover, endowed with exceptional acoustic properties (sounds are amplified up to 16 times).
These acoustic characteristics and shape prompted Michelangelo di Caravaggio, who visited Syracuse in 1608 in the company of the Syracuse historian Vincenzo Mirabella, to name it the Ear of Dionysius, thus giving force to the 16th-century legend that the famous tyrant Dionysius had this cave built as a prison and locked his prisoners in it to hear, from an opening from above, the words magnified by the echo. In fact, although to the detriment of suggestion and legend, it is worth knowing that the shape of the cave is simply due to the fact that the excavation began from above, following the bottom plane of a serpentine aqueduct, and went wider and wider in depth, as an excellent quality of rock was found. Proof of this on the walls are clearly observable traces of the stone quarrymen’s work tools and, in a horizontal direction, the detached planes of the extracted blocks.