Khuko, Rift lake and protected area in Adygea, Russia

Khuko is an oval lake in the Western Caucasus, 260 m long and 150 m wide, lying at 1,744 m on the border of Krasnodar Krai and Adygea. It has no inflow or outflow, yet its level stays constant all year. Its banks are little indented, with slopes rising 5 to 100 m and a broad beach in the northeast.

The lake's origin is not fully settled. It is thought to have formed in a basin created by tectonic cracks along the Kurdzhipsko-Adler fault zone, where erosion and frost weathering broke up the rock. A nearby drained basin once held a lake twice Khuko's size before its water broke through the watershed toward the Pshekhashe River.

Adyghe people consider Khuko sacred, believing it is a remnant of an ancient sea still linked to the Black Sea. In droughts, villagers from nearby auls took water from the lake and poured it into rivers, expecting rain once it reached the sea. On the eastern slope of the basin stand two upright stones, one bearing a coloured image of a fish, though no fish live in the lake.

The lake can be reached via marked trails from the nature reserve entrance, with the best conditions during summer months. Plan for mountainous terrain and weather that changes quickly at this high elevation.

No river feeds or drains the lake, yet its level stays constant all year. Despite a rock painting of a fish on the eastern slope, no fish, other animals or even algae live in the water.