The Lost City of the Kalahari

The account

In 1885 the showman-explorer 'Farini' came out of the Kalahari claiming he had found a lost city, cyclopean walls and cemented stone half-buried in the sand. Thirty expeditions have hunted it since and turned up not a single brick. The likely answer, a geologist concluded, is dolerite: an igneous rock that weathers into straight, regular blocks that look exactly like a wall. A lost city that may only ever have been the desert playing a trick, but the search refuses to die.

Leads, where the trail points now

• Guillermo Farini's 1885 account placed a ruined stone city in the Kalahari; the search zone is the dry country near where South Africa, Botswana, and Namibia meet.
• Decades of expeditions concluded Farini saw natural rock formations, the Eierdop koppies near Rietfontein, eroded to look like masonry; that is the leading explanation.
• The open work for a believer is reconciling Farini's route and photographs with the geology; no artificial structures have ever been confirmed.