Prometheus Cave is the largest cave in Georgia, in the limestone hills of Imereti near the town of Tskaltubo, twenty-two halls dissolved out of the rock over millions of years, six of them opened along a lit walkway of 1.4 kilometres that ends at an underground river you can leave by boat. The halls are vast, ceilings bristling with stalactites and floors rising in heavy stalagmites, curtains and columns, and the lighting picks them out in colours that change as you walk; the largest chamber is the size of a cathedral, and the air stays at about fourteen degrees all year, so the cave is a refuge from the summer heat of the plain. The path descends through the six halls in about an hour, with a guide, past a lake, petrified waterfalls and a stone forest, and at the far end the walkway meets the river, where a boat carries you a few hundred metres through a flooded tunnel and out into daylight instead of walking back.
The cave was found in 1984, opened to visitors in 2011, and named for a Greek myth that legend set in this very region: Prometheus, chained to a rock in the Caucasus for stealing fire from the gods, and the Argonauts, who sailed to Colchis, the kingdom of western Georgia, for the Golden Fleece. The six halls carry those names, Argonauts, Colchis, Medea, Prometheus and the rest, given at the opening; the Caucasus already had its own fire-stealer, Amirani, chained to a peak in Georgian legend for the same crime, and the locals will tell you the Greek one is a copy. Tskaltubo, the town nearby, was a spa resort of the Soviet Union, and its abandoned sanatoriums stand in the park a few kilometres from the cave. Prometheus Cave is a cathedral under a hill named for a thief, and the way out is by water.