Socotra is one of the world's last unspoiled island chains -- an archipelago off the coast of Yemen that has wildlife so diverse it has been described as the Galapagos of the Indian Ocean. A third of Socotra's 825 plant species, 90% of its reptile species and 95% of its land snail species do not occur anywhere else in the world, according to UNESCO, which added the archipelago to its World Heritage List for its natural beauty.