Lac Abbé is a salt lake on the border of Djibouti and Ethiopia, in the Dikhil region, whose dried-out plain bristles with hundreds of limestone chimneys up to fifty metres tall, some still steaming, on the one spot on land where three plates of the Earth's crust are pulling apart fast enough to be watched, and it is reached across the Afar plain by four-wheel drive and slept beside in Afar huts. The lake is the end of the Awash river, which flows out of the Ethiopian highlands and dies here in the desert without reaching the sea, and it has shrunk as the water was taken upstream, leaving a plain of cracked salt; the chimneys were built underwater by hot springs rising through the lakebed, which deposited their calcite around the vents, so each tower could only grow while it stood submerged, and the whole field formed under the lake before it withdrew and left them standing in the air, taller than a three-storey building, with steam and hot water still coming out of a few. The ground is the Afar triple junction, where the Arabian, Nubian and Somali plates separate and a new ocean is being born.
The camps are dome-shaped toukoul huts of bent branches and woven mats, arranged in the open with no artificial light, and after the moon sets the Milky Way is startlingly bright over the chimneys. Dawn is the hour: the towers stand black against the sky as the light comes, the steam shows, and flamingos and other wading birds feed in the saline shallows before the heat sets in, which by midday is severe. The drive in from Dikhil is unpaved, across open plain shared with camels, wild donkeys and Afar herders moving their goats, and the Afar of the camps guide the walks among the towers. Planet of the Apes shot its alien landscape here in 1968. Lac Abbé is a forest of stone chimneys on a floor that is splitting, and the night among them is the visit.