The grotta is located near the highest part of the little rocky relief, on a rectangular terrace which verges on the Greek theatre and opens at the centre of a stone wall where a closed portico in the form of an "L" was once found. At the entrance there were statues dedicated to the Muses, three of which are still preserved and are on display at the Museo archeologico regionale Paolo Orsi. The fountain is dedicated to the Ancient Greek cult of the nymphs, nature goddesses. The name nymphaeum for a monumental, decorated fountain derives from this. The Syracusan nymphaeum is thought to have been the ancient location of the Mouseion, seat of the artistic guild, where the Syracusan actors gathered before descending into the theatre to put oncomedies and tragedies in the time of Epicharmus and Aeschylus. Regarding the Grotta del Ninfeo, the Syracusan Giuseppe Politi wrote in the nineteenth century: The grotto has a vaulted ceiling and inside it there is a rectangular tub in which the water collects before cascading from a cavity located at the bottom of the rock wall. Next to the entrance, there are some votive aedicula which were used for hero cults. To the east of the Grotta del Ninfeo, the last watermill from the Spanish period remains visible even today. It took water from the grotta and redirected it into the theatre after using it to mill grain. From nymphaeum, one continues to the Via dei Sepolcri and from there to the summit of the hill, where there are other Graeco-Roman monuments. The water that flows into the Grotta derives from two separate aqueducts, both of Greek date; one is called the Acquedotto del Ninfeo after the Grotta, while the other is the Galermi Aqueduct.
Depiction by Jean Hoüel
During one of his trips to Syracuse in the second half of the 1700s, the painter Jean-Pierre Houël depicted the Grotta del Ninfeo as he found it. The gouache shows a much deeper grotta than today, with water descending towards the theatre, where the mills were installed. In the grotta, some women are busy making cloth.
