Why to go now: Known for its vast grassland plains surrounded by mountains and desert, Mongolia is the most sparsely populated independent country in the world. But the legendary steppe of Genghis and Kublai Khan will not remain untrammeled for long. Mineral exploration is threatening the country's age-old nomadic way of life. Fueled by a mining boom, Mongolia's economy grew at a record 17.5 percent in 2011. According to Citigroup Global Markets, it will continue to grow at an average of 9.7 percent, the fastest in the world, through 2030. That means the great wide open spaces of Mongolia are shrinking at an ever faster pace.

How to get there: In 1992, Nomadic Expeditions began leading trips to Mongolia. Founder Jalsa Urubshurow served as adviser to the prime minister of Mongolia on tourism, and designed and founded Three Camel Lodge, an award-winning eco-lodge in the Gobi Desert.