Lying 230km to the southeast of Athens, Santorini (officially known as Thira) is the southernmost of the islands of the Cyclades group. Santorini ows its horseshoe shape to a massive volcanic explosion which happened around 1500 BC and destroyed the centre of the island, only leaving a collapsed caldera with a diameter of roughly 12 km. The central lagoon is surrounded by steep cliffs and is 400 m deep. Santorini is one of the few islands of the Cyclades group with a major airport. It is a very scenic island, with breathtaking views from the top of the cliffs at sunset.