The grotto of the visionaries of Melibea, also called Grotto of Sibylla, is located directly under the Church of San Giovanni Battista, built in 1555 by Jesuit monks on the promontory of Capo Boeo. Tradition connects this crypt with the name Sibylla Cumana, also known as Sybil Sicula. Sybil (or Cybele) was called in ancient times sibyl future, clairvoyants.

The Church of San Giovanni Battista was first erected on this place, on the contrary, together with the Church of Santa Maria della Grotta she was part of the ancient Abbey Padre, Basiliani.

The grotto of Sibylla is located at a depth of about 5 meters under the ground and consists of a Central circular niches related with two areas – one facing North, the second to the West. Niche carved directly into the rock, covered with a kind of low canopy of stone, which made the Dormer window – it is connected to the higher floors of the Church. There you can see the square Chan, not too deep, designed to hold water. Northern room, also carved in the rock that has the shape of a semicircle. At floor level is a spring that fills a square Chan. Before this room features a large stone altar carved with the image of Saint John the Baptist (Giovanni Battista in Italian). The altar, dated to the 15th century, is of immense value. The Western room of irregular shape, probably, was partially constructed from the well.

Given the presence in the cave spring and the proximity of the sea, the nation was born the legend that is here Ulysses came to quench their thirst. It is also said that in this very grotto lived Sibilla Cumana is one of the most famous oracles of antiquity. Near the grotto is something like a bed that seems carved into the rock, according to legend, on it and rested Sybil.