The salt works of Tegidda-n-Tessoumt — the salty water source in Tamasheq — lie about 80 km north of In-Gall, in a salt-rich depression at the foot of the Aïr Mountains. The complex of perhaps a thousand small clay-lined evaporation basins is one of the last places in West Africa where salt is still produced by the medieval Saharan method: brackish spring water is led into shallow pans, allowed to evaporate over days in the desert sun, and the crystallised salt scraped up in cakes.
The salt is then loaded onto camel caravans — fewer now than fifty years ago, but still in operation — and carried south to the markets of Agadez, Tahoua, and further into Hausaland. A visit is the closest you can get in the modern world to the trans-Saharan salt trade of the medieval period. Travel only with a local guide and the appropriate permissions.