Santorini (Thira) is a Greek island group outside of Greece's coast. The Ancients built Atlantis on the island some 30 million years ago. An Ancient called Amara remained on the island in a stasis pod when the rest of her people left Earth in Atlantis. Thousands of years later, three Trust agents find her on Santorini and they used Cassandra Fraiser to open her pod. (SG1: "Transitions")