The Salar de Uyuni is the largest salt flat in the world, a sheet of white about ten thousand square kilometres in extent, lying high in the southwest of Bolivia at roughly 3,650 metres. It formed when prehistoric lakes dried up, and what remains is a crust of salt several metres thick, with brine beneath it. Under a hard sun the surface is blinding, and the horizon disappears, so that the land and sky merge, and distance becomes meaningless. It is one of the strangest places a rider can reach.
Riding on the salt is nothing like riding on a road. The surface is hard and flat, patterned with hexagonal ridges where the salt has dried, and in the dry season you can ride across it at speed in any direction. The difficulty is navigation. With no landmarks, you can lose your bearings, and a GPS or an experienced guide is essential. The glare calls for good sunglasses, and the sun at this altitude burns quickly. The wind can be fierce in the afternoon. In the wet season, from roughly December to March, a thin layer of water covers the flat and turns it into a vast mirror, which is lovely to see but treacherous to ride, as the water hides soft patches and corrodes the machine. Salt is brutal on a motorcycle, getting into brakes, chains and electrics, so wash the bike thoroughly with fresh water afterward.
There is a good deal to see. Isla Incahuasi, an island of fossilised coral rising from the salt, is covered in giant cacti, some of them centuries old. Hotels in the area are built partly of salt blocks, and the town of Colchani on the edge of the flat produces salt for sale. Beneath the salt lies one of the world's largest reserves of lithium, a metal that has made the place a topic in the global debate over batteries. The railway cemetery outside the town of Uyuni, where old locomotives rust in the desert, is another curiosity.
The practical points are serious. Fuel is available in Uyuni, and not out on the salt or on the tracks nearby, so fill up and carry extra. Water is vital, and so are warm layers, as the nights are freezing. Flamingos live in the high lakes to the south.