Cafe in Oia, Santorini, Greece

Santorini  is an island in the southern Aegean Sea. Santorini is essentially what remains after an enormous volcanic eruption that destroyed the earliest settlements on a formerly single island, and created the current geological caldera. A giant central, rectangular lagoon, which measures about 12 by 7 km, is surrounded by 300 m  high, steep cliffs on three sides. The main island slopes downward to the Aegean Sea. On the fourth side.  Source