Morning: Laguna Cejar
By mid-morning the turn-off for Laguna Cejar arrives, leading down a dirt track into the heart of the Salar de Atacama. The salar — the largest salt flat in Chile and among the richest lithium deposits in the world — is not the smooth white sheet of Uyuni but a broken, crystalline crust of strange textures and violent brightness. Cejar sits within it: a sinkhole lake some 18 kilometres from San Pedro, its water a deep calypso blue against the white salt surrounds. The salinity here runs as high as 280 parts per thousand at its densest — comparable to the Dead Sea — which means you float without effort, lying back on a surface that refuses to let you sink. An hour here is about right: time to swim, rinse off (the showers are cold), and walk the short trail around the salt margin. Sunscreen is not permitted in the water, so apply it after.