A renowned curiosity at the heart of the Garden of Paradise is the ear-shaped artificial grotto known as the Ear of Dionysius. According to Caravaggio, Dionysius must have had it built so he could listen in on the conversations of the prisoners, but it is most likely that the grotto – 23m high and 65m deep – was dug out as a rock quarry and later used as a sounding board for theatrical performances.
