In a short distance from the settlement of Antissa is the cave Spilios of Antissa, which is inextricably linked to Greek mythology, as it was the place of worship of Orpheus in ancient times.
The cave is opened in a hill made of limestone rocks that are about 298-251 million years old. The limestone elevation emerges from among the newer volcanic rocks that surround it and reveals the particularly intense tectonic activity of the area.
The factors that contributed to the creation of the cave were tectonic action and karst erosion. The karst formation is created by the movement of water within the tectonic zone of a large tectonic fault in the limestone rock.
The entrance of the cave, which has an opening of 10 meters wide and 12 meters, is called “Chaos” by the locals, and is easily recognizable and visible from the Kalloni – Sigri road.
Inside it are observed prehistoric traces of human presence, as well as two mudstone constructions.
According to Greek mythology, the head of Orpheus washed up on the shores of northern Lesvos and was carried by the inhabitants into the cave, where it functioned as a sanctuary, which continued to provide prophecies, thus making the oracle of Orpheus well-known in the ancient world.