<p>A migratory stop along the African-Eurasian flyway, the <strong><a href="http://travel.nationalgeographic.com/travel/countries/kenya-guide/" target="_blank">Kenya</a> Lake System in the Great Rift Valley</strong> is a cageless aviary—populated by 13 endemic, threatened bird species. Up to four million lesser flamingos congregate among nesting great white pelicans and roving flocks of spoonbills, grebes, and storks. More than 100 migratory bird species make this their home November through March, which local safari guide Preston Mutinda says is prime bird-watching season. A two-hour drive north of Nairobi, the shallow, alkaline bodies of water combine to cover 122 square miles, with Elmenteita, Bogoria, and Nakuru Lakes arranged, as Mutinda puts it, “like pearls on a string along the Great Rift Valley.” The valley’s floor ripples with hot springs, offering a rich feast of green algae for foraging fowl. Zebras, black rhinos, cheetahs, lions, and giraffes also wander along the shoreline—but even they play supporting roles for the star attraction, the flurry of pink taking flight.</p><p>This and other UNESCO World Heritage sites are featured in “2012 World Wonders” in the August/September 2012 issue of <em>National Geographic Traveler.</em></p>