Part of the Cyclades, Santorini is still part of an active volcano which is probably the only volcano whose crater is in the sea. Born from numerous volcanic eruptions, Santorini is a top Mediterranean destination and may be the most melodramatic of all the Greek islands. Now crescent shaped, with a dramatic landscape of cliffs towering over an enormous crater. Its two principal towns, Fira and Oia, are perched on the edge of the caldera and overlook the Mediterranean. Click here to read more about Santorini and read a great article, The Magic & Mystery of Santorini.