Great Indian one-horned rhinoceros graze peacefully along the Brahmaputra River here, wallowing and sometimes swimming in the cool water on hot days. They are unknowingly indebted to a British noblewoman for the beautiful national park where they came back from the edge of extinction.

Lady Curzon learned from tea plantation friends in 1904 that only about a dozen remained of these prehistoric-looking two-ton (almost 2,000-kg) beasts up to 13.3 feet (4 m) long, whose deeply folded gray skin makes them look as if they are wearing coats of armor. Once thousands roamed the Indo-Gangetic plains. (Marco Polo thought when he saw them in 1271 he had found the fabled unicorn.) Tea clearing had wiped out many of them; merciless shooting had done the rest. Lady Curzon told her husband something had to be done and in 1905, this inviting riverine forest and grassland was set aside for them; shooting was banned in 1908.

Now Kaziranga National Park is a U.N World Heritage Site, 261 square miles (675 km2) in the Assam district of northeast India, protecting the world’s largest population (at recent count 1,129) of these great, lumbering but agile creatures which can trot along at 20–25 miles an hour (35–40 kmh). In the process many other species were saved as well, including more than a dozen of India’s most threatened mammals and some near-extinct bird species.

Tigers and leopards find shelter and food, sharing the mixed short and tall grasses and woods along the Brahmaputra River with capped langurs, hoolock gibbons, leopards, and the sambar, swamp, hog, and muntjac or barking deer. If hungry enough, tigers will even take on formidable wild boars or water buffalo (largest herd in India is here). Working as a team, tigers have even brought down enormous gaurs—largest Asian oxen, up to 11 feet (3.3 m) long, 7.2 feet (2.2 m) high at the shoulder—or, rarely, a young Indian elephant.

Gray pelicans have a noisy nesting colony, and more than 300 other bird species find permanent or seasonal homes, some from as far away as Siberia. In moist forests are green imperial pigeons and multihued peacock-pheasants, around the river lesser adjutant and black-necked storks, and overhead, Pallas’ and gray-headed fish-eagles. At recent count some 25 Bengal floricans were here.

Insectivorous sloth bears work on termite mounds. Gangetic dolphins streak through river waters where dragon-like, yellow-spotted black monitors up to eight feet (almost 3 m) long are propelled by rudder-like tails at a more stately pace. Playful otter families enliven interconnecting streams and numerous small lakes or “bheels.”

King cobras, world’s largest venomous snakes up to 18 feet (5+ m) long, make brushy nests, leading secretive woodland lives—luckily, since their bite can kill an elephant in a few hours, a human in 15 minutes.

Kaziranga is flooded every year when the Brahmaputra River overflows during monsoon rains from June to September. Formerly many animals drowned, but islands have been built where they now can safely retreat during rising water. Poachers still kill rhinos every year to satisfy a demand for horns (not true horns but compressed keratin and hair) used in high-status dagger handles or ground up for aphrodisiacs and other Oriental folk medicines to treat ailments from strokes and convulsions to nosebleeds. Rhinos’ regular habits, using the same paths every day, make them easy prey for pit traps or ambush shooting. But determined efforts on several fronts (including shoot-to-kill orders to rangers) have been effective. Demand is gradually decreasing, rhino numbers gradually rising.

Many South and Southeast Asian countries have banned trade in rhino products. The World Wide Fund for Nature has funded anti-poaching units. The Rhino Foundation for Northeast India has provided guards’ supplies. Kaziranga is now considered the safest homeland for Rhinoceros unicornis, and a landmark in India’s conservation history.

Another rhino problem poses special difficulty—how to protect these vulnerable, shortsighted vegetarians against an increasing number of encounters with an equally endangered and more dangerous animal, the rhino’s arch-enemy in the natural world: tigers.

Best times are November–March, mild and dry, becoming warmer, more humid as May–September monsoons approach. Park is closed May–October.

Best way to move around the park is by elephant, which can be hired at Mihimukhi (book ahead).