Dia is a small island in the north Crete, in the region of Heraklion. It is located about 7 nautical miles from Heraklion, with only one local guard. Also there is one small and beautiful church of Analipsis (Ascension of Christ). Detailed aerial photos also pointed out traces of settlements, confirming the hypothesis that the island was previously inhabited. The island had a small area where vine was grown by fishermen, till 1937.

Dia is an archeological site and part of the European Network of Nature (Natura) 2000, due to the high biodiversity of the island.There are many protected endemic species of flora and fauna such as snails (Albinaria retusa), lizards (Pdacris erchardii schiebeli), wild rabbits (Oryctolagus), a falcon named “mavropetritis”, the well-known kri-kri and protected plants such as Carlina diae. There are no poisonous animals or fish.

According to the legend, the island was created by Zeus: Zeus, from his throne in Olympus looked to his birthplace, Crete, and he was surprised to see Cretans hunting his beloved Cretan wildgoats. The goats were children of Amalthea, the goat that nurtured Zeus with milk while he was hiding from his father Kronus in Diktaean Antron Cave He was so angry, that he decided to kill all Cretans. Immediately, he blew a lightning into the sea and a monster was born to destroy the Cretans. Then, Poseidon, the god of Sea, try to stop him reminding him of Kourites(Cretans) who protected him from his father Cronus who was about to eat Zeus. Zeus immediately changed his mind and he took two pieces of rusk and threw them towards Crete. When the monster tried to eat them, Zeus with a thunderbolt petrified the dragon with the rusks. This is how Dia and the two islets of Paximadi and Petalidi were born, and the islet looks like a giant lizard when viewed from the city of Heraklion.

According to another legend, Theseus, after killing the Minotaur, fled to Dia with Ariadne.

Moreover, the French oceanographer Jacques-Yves Cousteau carried out an underwater exploration with a special bathyscaphe around Dia in 1974-1975 and seven wrecks were found on it.
In 1976, he discovered, at the bottom of the sea, square and rectangular rocks. These rocks formed an artificial pier and it was the ancient port between Heraklion and Dia. According to Cousteau, it was the largest and most important port of Knossos.