These are the islands, the world thinks of when hearing the name Greece. Small rocky islands whith the small white cubic rock houses and churches with blue painted cupolas. They were named in the Classical Antiquity, as they are located in a circle around the religious center Delos, after the Greek word kyklos (circle).
There are caves on the islands, the northern islands are built of limestone and karstified. But although the white limestone is typical for the Cyclades, there are many famous volcanioc islands. The most renowned is Santorin, an island shaped like a new moon, which is the rim of a huge caldera. A circular island in the center of the caldera is the new cone of the volocano and shows several signs of volcanic action.
But the explosive volcanism of this Aegean volcanoes is not appropriate for the formation of lava caves. Lava tubes are formed by calm lava flowing downhill for a long time. The volcanoes of the Cyclades tend to explode, like Santrini, which originally was a normal volcanic island, but exploded in 1628 b.C., most likely destroyed the first civilization of the Mediterranean, the so called Golden Age and became its modern shape. The explosion is interpreted by some archaeologists as the destruction of Atlantis, which would mean that either Santorini was Atlantis, or a nearby island, which was destroyed by the tsunami, the explosion generated.