Over millions of years, the swift Charyn (Sharyn) River has carved a truly spectacular 150m- to 300m-deep canyon into the otherwise flat steppe some 200km east of Almaty, and time has weathered this into some weird and colourful rock formations. The most popular section, the Valley of Castles, is accessible by regular car; for the rest, you need a 4WD. You can get here by guided tour from Almaty, drive yourself, or come by public transport and then hike in.
From the car park where you pay the entry fee, a rough 3km road descends into the Valley of Castles (Dolina Zamkov), with some spectacular red rock formations reminiscent of Utah or Arizona, before ending at the Charyn River. It's an idyllic spot, but apart from having a quick and very cold dip near the shore, swimming is dangerous, as the river is deceptively fast.
Armed with your own wheels and a GPS (or on a tour with a knowledgeable operator) you can access more remote parts of the canyon, and marvel at the contrast in scenery. The Yellow Canyon is a sculpted, arid moonscape, while another precipitous viewpoint, high above the river, gives you tremendous views over bare, dark slopes, criss-crossed with precarious paths used by nimble-footed mountain goats. If you're lucky, you'll spot one through binoculars.
April, May, June, September and October are the best months to come: in the summer it gets seriously hot.
Allow yourself two or three days to properly explore the canyon, sleeping wild under the stars.