A very small center located on the cliff at a height of about 100 meters, which falls steeply into the sea. It is one of the first inhabited centers of the Salento peninsula. This is probably due to the fact that the coasts near Castro are dotted with caves that favored the settlement of prehistoric populations, such as the famous Zinzulusa cave.
The cave was called Zinzulusa by the local fishermen because of the "zinzuli", "rags", or the stalactites that hang from the ceiling like hanging rags. It is the largest of the caves in the area, discovered more than 150 years ago, and made accessible to the public in the 1950s. The cave develops along a path of about 150 meters, along which there are 3 main chambers: the Conca, the Duomo and the Cocito. Isolation from the outside world has meant that numerous forms of life developed inside with an extraordinary biodiversity compared to the size of the cave. The scientific/touristic importance is increased by the fact that numerous archaeological finds of human settlements and animals such as elephants, rhinos and hippopotamuses have been found inside the Zinzulusa cave.