The Gorges d'El Kantara lie about 35 kilometres north of Biskra, where the road from Constantine cuts through a dramatic limestone canyon only 40 metres wide but with walls rising up to 120 metres. The effect is abrupt and theatrical: approach from the north through olive groves and scrub vegetation, and then the gorge swallows you, the walls tower overhead, and you emerge on the other side into the beginning of the Sahara. Date palms, clear light, and the smell of warm sand announce the transition.
There is a small Roman bridge still standing in the gorge, and the ruins of the ancient settlement of Calceus Herculis on the plateau above. The village of El Kantara at the southern end of the gorge has cafes and a weekly market. The gorge is best visited in morning light when the canyon walls glow ochre. It is easy to combine with a trip to Biskra from Constantine, or as a half-day excursion from Biskra.