Santorini used to be circular (which is why it was called Στρογγύλη, Greek for ‘Circular’). The various parts of the volcano, such as Nea Kameni, Palaia Kameni, the Christiana islands, are places to visit. You can easily arrange a trip there by boat, but you can still enjoy these places from afar, as Fira offers magnificent views. Sadly, you can’t visit the underwater volcano of Columbo, unless you have scuba gear.

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 (7.5 by 4.3 mi), is surrounded by 300 m (980 ft) high, steep cliffs on three sides.