The Charyn River has cut roughly 90 kilometres of canyon through red sedimentary rock in Kazakhstan's southeast, about three hours by road from Almaty. Its best-known section, the Valley of Castles, is a two-kilometre corridor where erosion has left free-standing columns and fins that genuinely do read as ruined towers from a distance.
The walk down the valley floor is easy and largely flat, ending at the river itself, where a strip of unlikely greenery follows the water. Most visitors come as a long day trip from Almaty; there is basic accommodation at the canyon mouth for anyone wanting the light at either end of the day, which is when the rock does its best work.