A geological marvel, the Salar de Uyuni is one of the most perfectly flat areas on earth. There aren't hills, bumps, shadows, vegetation or depressions of any sort, and given the lack of visual reference points in such an immense area, one's sense of perspective is bound to become skewed.
The Salar de Uyuni is the most bizarre landscape I've ever stepped foot on, wresting the title away from South Dakota's Badlands, which I visited when I was nine. (That's a long run, Badlands, nothing to hang your head about!) Absolutely level as far as the eye can see, the salt flat becomes one of the world's largest mirrors when covered with water, and serves as an important orientation point from space. But we were visiting during winter, when the ground is cracked and dry.
Also called the Isla del Pescado thanks to its fish-like profile, the island of Incahuasi is situated smack in the middle of the enormous Salar de Uyuni. We arrived there midway through the first day of our tour. Covered by millennial cacti and composed of coral, the island is a stunning reminder that the salt flats used to be part of a gigantic lake.
Desolate, dusty Uyuni in the sparsely populated southwest of Bolivia feels like a town abandoned to the march of history. Founded in 1889, it was once a bustling railway hub connecting Bolivia's mines with the world beyond the Pacific. But the mines eventually dried up, and the trains stopped running. Rather than decommissioning and selling them as scrap, depressed Uyuni left the useless locomotives to rot in a fascinating "train cemetery" just a few kilometers outside the city.