Santorini (san-tuh-REE-nee). Aegean island, previously known as Thera, constituting the partially collapsed cone of a volcano. The volcano, purged of its magma in a gigantic eruption, collapsed during the era of the Minoan civilization. The sea rushed in, rebounded when it hit bottom and then recoiled in a tidal wave that would have caused great damage to the coastal settlements of the neighboring island of Crete. This might have inspired the legend of the lost continent of Atlantis, an advanced civilization that supposedly disappeared beneath the waves.