Saklıkent's river does not run into the gorge — it comes out of its walls. Rain and snow that fall on the 3,024-metre Akdağ sink into the Jurassic limestone of the Taurus, travel through the massif underground, and burst back out through fault cracks at the canyon floor, where they become the Karaçay stream. Water and broken rock have worked together here for a very long time: the stream followed the fault lines, dissolved the limestone along them, and in places the roofs of old karst tunnels simply fell in. What they opened is an 18-kilometre fissure with walls rising close to 300 metres and narrowing, near the top, to roughly two metres apart. The name means "hidden city," and the gorge earns it — from the valley you would drive straight past the entrance without guessing what stands behind it. Turkey protected the canyon and its ridges as Saklıkent National Park in 1996, some 1,643 hectares on the Muğla–Antalya border, about an hour inland from Fethiye.
You enter along a wooden boardwalk bolted to the cliff, a couple of hundred metres of planking hung above the water, and it ends exactly where the walk turns serious. The springs pour in here, and to go on you must cross them: six to eight metres of fast, thigh-deep current, cold enough to sting, with a rope strung across as a handhold. Past it the gorge calms. You wade and scramble about four kilometres up a corridor of grey and pink limestone polished to a shine, under small falls, a strip of sky far overhead and sunlight touching the floor only near midday. That is where walkers stop; the remaining fourteen kilometres belong to roped canyoning teams. Back at the mouth, platforms over the stream serve trout, and people coat themselves in grey clay from the shallows.