DiaDia is an uninhabited small island, north of the island of Crete. It is located approximately 7 miles from Heraklion and administratively belongs to the Municipality of Chersonissos. It is 5 km long, 3km wide and 12 square kilometres in size. North of Dia, there are two small islets, Paximadi and Petalidi.

On the south side of the island there are four bays: the bay of Agios Georgios which is the only port of Dia and the beach of the island, the bay of Caparis, the bay of Panagia and the bay of Agrielia. On the east side, there is the bay of Aginara.

According to mythology, the island was created by Zeus. Zeus looked down to his hometown Crete from Mount Olympus and saw the Cretans chasing his favorite goats (kri-kri). Those goats were Amalthia’s kids while Amalthia was the goat that nurtured Zeus as he was hiding from his father, Saturn, in the cave of Diktaion Andron. He was so mad about it and he decided to kill them all. So, he blew a lightning in the sea and a giant monster emerged. Then, Poseidon, the god of the sea, reminded him of the protection that Kourites provided him as an infant and as a result Zeus decided to throw two rusks to the monster and then with a lightning he turned the monster into stone while the two risks was turned into islands and in this way Dia, Paximadi and Petalidi were created.

During the ancient times, Dia played an important role in the ship navigation, especially in Minoan and Medieval times and it was inhabited during Minoan Era. Dia was an island that provided guidance to the sailors over the period of time and it facilitated the entrance to the port of Heraklion by creating a natural “barrier” from the northern winds. Moreover, the French oceanographer Jacques-Yves Cousteau carried out an underwater exploration with a special bathyscaphe around Dia in 1974-1975. In 1976, he discovered, at the bottom of the sea, square and rectangular rocks near the bay of Agios Georgios. 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. Achilleas Tagaris in Illustrated History (vol. 143, 1980) states that the island was highly overgrown with rich forests and crystalline springs. Unfortunately, the forests were destroyed for the construction of ships and the springs died out. In addition to this, the eruption of the volcano of Santorini, around 1450 BC, destroyed Dia completely, as huge tidal waves ravaged every trace of life in their path.

Nowadays, Dia is integrated into the European Nature Network (Natura 2000) because of the vital biodiversity existing on the island and it is a controlled hunting area. There are many protected species of flora and fauna such as Albinaria retusa snail, Pdacriserchardiischiebeli lizard, Oryctolagus wild rabbits, a hawk named “mavropetritis”, the well-known kri-kri and plants such as Carlina diae.