Renowned Santorini (Thera), with its steep-walled caldera rim draped by whitewashed villages overlooking an active volcanic island in the center of a caldera bay, is one of the scenic highlights of the Aegean. The circular island group is composed of overlapping shield volcanoes cut by at least four partially overlapping calderas. The oldest southern caldera was formed about 180,000 years before present (BP), followed by the Skaros caldera about 70,000 years BP, and then the Cape Riva caldera about 21,000 years BP. The youngest caldera formed about 3600 years BP during the Late-Bronze-Age Minoan eruption that forced abandonment of the thriving Aegean Sea island. Post-Minoan eruptions beginning in 197 BC constructed a series of lava domes and flows that form two islands near the center of the caldera. A submarine eruption took place in 1650 AD outside the caldera NE of Thera. The latest eruption at Santorini produced a small lava dome and flow in 1950, accompanied by explosive activity.