A few dozen kilometers from Tozeur and Nefta are Chebika, Tamerza, and Midès, oases in a landscape of mountains that is one of the most moving sites in southern Tunisia. In this breathtakingly beautiful landscape, every oasis is different. In Chebika, a wadi runs down the side of a steep mountain, forming waterfalls and rivulets where frogs have made their home. The old village of Tamerza abandoned like a ghost village, looks out at a...