Salar de Uyuni Lake in southwest Bolivia covers over 10,000 square kilometers and is the largest salt flat in the world. It is perched close to the crest of the Andes, over 3,500 meters high. At the Salar de Uyuni, what you see is a stretch of white, with remote purple hills (which are actually active volcanoes!) dotting the horizon. It is, by far, one of the most exotic, even surreal, destinations in Bolivia. A view of this scene is very much like something from a dream.The fact that this vast tract is made up of salt (and notice snow or water) is fascinating. Salar de Uyuni originally was a huge saltwater lake or probably an inland sea, but mysteriously, the water vanished, and only the salt remained. The result? Aside from the Uyuni Salt flats, there is also the Coipasa Salt Flat (which is smaller) and Lake Poopo and Lake Titicaca.That is around 10 billion tons of salt, twenty-five times more than the amount of salt in Utah's Bonneville Salt Flats. The remote purple islands remind one of a scene straight out of an expedition to Mars. However, there is nothing 'alien' about the components of the salt flats. They are mostly composed of gypsum and halite. The Salar de Uyuni is near a Lithium reserve, which contains significant amounts of magnesium, boron and potassium. There are around 11 layers, each with around 2 to 10 meters of thickness. Salar de Uyuni is a favorite among photography aficionados, as the reflections produced by the flat provides some of the best shots. Now, when you visit the flats at the right time of the year, come November, the salt flat becomes even more interesting, as it becomes a feast of the flamingoes. These birds go to the salt flats in droves – thousands of Andean, Chilean and James flamingoes – so that they can breed. Another attraction is the La Isla del Pescado, which is dotted by huge cacti. This 'island' is named thus because it looks like a fish, especially as you approach. Also named Isla Incawasi, this is actually made up of fossilized coral.When you are in Salar de Uyuni, do try to stay at the salt hotel. Yes, everything is virtually made out of salt – the walls, the ceiling, the floor, the beds and tables – everything. Do remember to bring extra warm clothes, as temperatures can drop drastically.The lake is just off Uyuni, where one of the major industries is salt mining. Every year, around 25,000 tons of salt is extracted from the flat. The salt flat is at its driest from July to November. It is rainy from November to March. During this time, the flat is covered with a slim strip of water. The water provides a perfect reflection of the sky above. What's good about a visit to Salar de Uyuni is that you can also visit other tourist attractions nearby – the Laguna Colorada, the Laguna Verde and so many others.