25 Apr 2007, Bolivia --- Isla Incahuasi in the center of Salar of Uyuni, is covered with a specimen-quality forest of columnar cacti ("cactus corales temperatura"). The cacti grow on average only 1 cm/year, and some are over 12m high. The island's volcanic rock is coated in fossilized algae from a time when the Salar was an inland sea, and the climate much wetter. It is a very popular tourist destination, with some fifty jeeps (primarily back-packer tourists) visiting daily. The island is located near the center of the Salar de Uyuni, the largest salt flat in the world, covering over 10,000sq. km. at an elevation of 3,650m. --- Image by © George Steinmetz/Corbis