Kolmanskop is a German town in the Namib desert with sand dunes inside its houses. Step through the doorways and you find a ridge cresting across a ballroom floor, a corridor filled to the knee, a bedroom wall half-buried in ripples, and the paint still up in pale green, blue and peach. The town was built on diamonds picked off the dunes by hand. In 1908 a contract railway worker, Zacharias Lewala, shovelling drift off the line near Lüderitz, found a glittering pebble and handed it to his supervisor, August Stauch. By 1912 the field around Kolmanskop was producing roughly a tenth of the world's diamonds, and the money bought 350 residents a ballroom, a theatre, a skittle alley, a saltwater pool and an ice factory. Then in 1928 far richer stones turned up 270 kilometres south. People left the furniture where it stood, and by the late 1950s the last of them had gone.
The sand is still arriving, and the rooms are still filling. A few buildings are kept swept and furnished; the rest are left to it. In the old hospital stands the first X-ray machine south of the equator. It was pointed at people as often as at illness: workers leaving the diamond fields were X-rayed to see whether they had swallowed a stone. Kolmanskop is not abandoned in the strict sense. It sits inside a diamond area that is still restricted, Namdeb runs it as a museum, and you need a permit to walk in. Photographers come at sunrise, when the light reaches through the empty window frames and before the day's footprints cross the sand.