Geocachers hoping to log a smiley for  Salar de Uyuni (GC2M6GC) encounter one of the world’s largest salt lakes. Werwolfi created the difficulty 3, terrain 4 EarthCache at the beginning of 2011.

The cache page reads, “Driving across it [Salar de Uyuni] is one of the weirdest and most fantastic experiences anywhere on the continent, especially during June and July, when the bright blue skies contrast with the blinding white salt crust and in the rainy season they turn into a gigantic mirror.”

To log the cache, adventurers must explore the geological site and answer two questions on the cache page. The answers must then be emailed to the cache owner. A photo must also be taken at specific coordinates.

Travel to the salt lake region will take geocachers to an altitude of 3650m (11,970ft). As one geocacher noted, not all equipment can endure the harsh environment, “We had a great day on the Salar de Uyuni and the Islands, but the engine of one of our Land Cruisers gave up.” So far, at least six geocachers have made the voyage and logged the EarthCache.

Continue your exploration of some of the most engaging geocaches from around the globe. Explore all the Geocaches of the Week on the Latitude 47 blog or view the Bookmark List on Geocaching.com. If you’ d like to nominate a Geocache of the Week, send an email with your name, comments, the name of the geocache and the GC code to pr@groundspeak.com.