Being immersed in hot sand has long been recognized as good for arthritis, rheumatism and spinal problems, and sufferers come from all over Europe to be treated in Siwa. The treatment is offered from June to September, and involves being buried up to your neck in sand at Jebel Dakhrour. Treatment courses last three to five days, with twenty-minute sessions (two or three daily) interspersed by sips of medicinal tea to induce sweating, and hours of rest in a tent or mud hut. Sand saunas can be arranged through the Al-Zaytuna Resort (£E300/person/day including all meals). Don’t bring any valuables to the isolated sand-bathing sites, as thefts by locals at Dakhrour have been reported.