Kaziranga

Fewer than 200 were left in the north Indian state of Assam a century ago. Agriculture had taken over most of the fertile river valleys that the species depends on, and the survivors were under relentless assault by trophy hunters and poachers. Kaziranga was set aside in 1908 primarily to save the rhinos. It held maybe a dozen. But the reserve was expanded over the years, given national park status in 1974, and named a World Heritage site in 1985. During the late 1990s it grew again, doubling in size (although legal issues remain to be settled). Now Asia's premier rhino sanctuary and a reservoir for seeding other reserves, Kaziranga is the key to R. unicornis's future.

A thundering conservation success story, the park also harbors almost 1,300 wild elephants; 1,800 Asiatic wild water buffalo, the largest remaining population anywhere; perhaps 9,000 hog deer; 800 barasinghs, or swamp deer (it's a main enclave of this vanishing species); scores of elk-like sambars; and hundreds of wild hogs.