Chrysospilia is a unique natural monument.
It is a remote cave on the north-eastern side of the island, about 30 metres above sea level, with a significant speleological and archaeological interest. It has a length of 300 m and two main chambers joined to each other by a small corridor. Roman wells and a large number of shells have been found on the floor of the first chamber, while the second chamber is decorated with impressive stalactite formations.
However, the element that makes Chrysospilia a unique monument of the global cultural heritage is the large number of ancient names covering its walls and ceiling. The names date mainly from the 4th century BC and belong to young adults who arrived here from all parts of Greece. The young adults who managed to enter the main chamber inscribed their names on the walls, thus leaving a trace of their visit.