In the dry season, the salt planes are completely flat expanses of dry salt, but during the wet season, the neighboring Lake Poopó overflows and floods Salar De Coipasa and Salar de Uyuni covering both deserts with a thin sheet of water that looks magnificent under the vast open sky.
Underneath the surface of the Salar is a lake of brine 2 to 20 meters deep. The lake is covered with a solid salt crust with a thickness varying between tens of centimeters to a few meters. The center of the Salar contains a few "islands", which are the remains of the tops of ancient volcanoes which were submerged during the era of lake Minchin. They include unusual and fragile coral-like structures and deposits that often consist of fossils and algae.
The Salar contains large amounts of sodium, potassium, lithium and magnesium as well as borax. With estimated 5,400,000 tonnes, Bolivia holds about half of the world's lithium reserves, most of those are located in the Salar de Uyuni. Despite the large reserve, there is currently no mining plant at the site, as the Bolivian government doesn't want to allow exploitation by foreign corporations. Instead, it intends to build its own pilot plant with a modest annual production by 2012.
Salar de Uyuni is estimated to contain 10 billion tonnes of salt, of which less than 25,000 tonnes is extracted annually.
Salar de Uyuni attracts tourists from around the world. As it is located far from the cities, a number of hotels have been built for accommodation. Due to lack of conventional construction materials, many of them are almost entirely built with salt blocks cut from the Salar - including walls, roof and furniture. The first such hotel, Hotel de Sal Playa, was erected in 1993-1995 in the middle of the salt flat, and soon became a popular tourist destination. Many more hotels and hostels made out of salt were constructed later.
Hotel de Sal Playa was previously covered on Amusing Planet.