This is the world's largest salt flats at over 10,000 square kilometers. Located in the Altiplano in Bolivia's south (near border with Chile and Argentina). The Altiplano is a high plateau surrounded by the mountains with no drainage outlets, making for a unique landscape - and in this case huge salt industry.
Our friend Esther who grew up in Bolivia told us it's a must-see. We are now looking at adding a couple of days there to the trip. There's a train we can take from Chile's Atacama Desert across the Andes, which is closer than La Paz and looks more pleasant than bussing it or renting a 4x4.
Bolivia is turning out to be quite an interesting place. Can't wait to actually be there and see all the superlative parts, the guide books promise.
(This image is linked via Wikimedia Commons; Credit: Salar de Uyuni. Bolivia January 2007 Picture Ezequiel Cabrera)