Ténéré Desert

The Tenere is proper Sahara, a sand sea empty enough that a single acacia standing alone in it for centuries became a landmark on maps before a truck finally knocked it down. Salt caravans once crossed to Bilma and Fachi from here, and the ruins at Djado lie further out still, among the most remote sites anywhere on the continent. None of this has been safely reachable by ordinary travellers for well over a decade, and the reserve that protects it has stood on the world heritage danger list since 1992. It remains a place of record rather than one to plan a trip to.