Charyn Canyon is a gorge up to 300 metres deep that opens without warning in the flat steppe of southeastern Kazakhstan, in Almaty region near the Chinese border, cut by the Charyn river through red sandstone, and one stretch of it, the Valley of Castles, has eroded into rows of towers and columns like a city nobody built, walked along a wide track from the rim to the river. The steppe gives no hint until the last few steps, and then the whole valley is below at once, three kilometres of red walls closing to eighty metres apart and opening again; the towers survive because they are capped by a harder layer that sheds the rain, and the rock is up to twelve million years old, laid down by rivers and lakes, so that a climate team once picked this canyon of everywhere on Earth for its cores, since almost no land lies further from an ocean and the rock here records the continent's own weather without the sea's influence. The track drops from the car park at the top and threads the valley floor to the Charyn river at the bottom, where there is shade and a small camp.
Twenty kilometres downstream at Sarytogay a forest of Sogdian ash lines the river floodplain, the only grove of its kind left in Kazakhstan and a leftover from a wetter world, a Paleogene relict that has hung on by drinking the river's groundwater while the land around it turned to steppe and desert, and it turns gold from late September through October. For a few weeks after the snow goes the steppe above the canyon flowers, wild tulips, poppies and irises across ground that looks dead for the rest of the year. The canyon is three hours from Almaty and done as a day trip or with a night in a yurt on the rim. Charyn is a crack in the steppe full of castles, and the river at its bottom made them.