Chyulu Hills

190km (118 miles) SE of Nairobi

Said to be the setting for Ernest Hemingway's Green Hills of Africa, the Chyulu Hills -- hundreds of small, voluptuous green mounds composed of ash cones and craters -- are among the most recently formed geological phenomena on Earth, clocking in at around 400 or 500 years. Ranged between Amboseli to the north and Tsavo farther south, the hills divide the southern extremes of Maasailand from the traditional lands of the Wakamba people. Volcanic vents, deep ash craters, and dark lava flows punctuate the rounded domes, and valleys of lush green forest spread between the hills to form a landscape of startling beauty, backed by drop-dead views of Kilimanjaro in the near distance.

Little-known and still undeveloped, the Chyulus remain blissfully remote -- even the national park here lacks serious infrastructure. Nutrient-rich volcanic soil and rock from the last eruptions here -- two of the cones, Shetani and Chainu, blew their lids as recently as the mid-19th century -- support a dense forest that spreads through the seemingly endless surrounding plains. Volcanic activity here has left some intriguing geographic phenomena, too, including Leviathan, the world's longest lava tube.

Despite the absence of permanent surface water, the Chyulu ecosystem has evolved into some of Kenya's most picturesque terrain. Rough grassland and thicket give way to patches of montane forest along the spine of the hills, while mature flat-topped acacia woodland covers the area immediately below, with impenetrably thick bush growing from the nutrient-rich lava flows beneath. It's Mt. Kili, though, that's largely responsible for sustaining the vibrant ecology here. Rainwater and snowmelt running off Africa's highest mountain percolate through the Chyulu's porous lava-rock underbed to form deep, fast-flowing subterranean rivers that not only feed the hills, keeping them green and lush throughout the year, but are believed to feed many permanent freshwater sources in the surrounding plains, notably the Mzima springs (Mombasa's principal water source) in Tsavo West and both the Tsavo and Galana rivers.

Along with some intriguing geographic phenomena that are a result of volcanic activity here, the hills are a good place to search for 37 species of orchids, most of which are epiphytes supported by the heavy mists. And all around the Chyulu Hills, a densely forested environment and more fantastic rock-studded hills and mountains provide shelter for a brilliant variety of animal life. Buffalo, zebra, giraffe, lion, leopard, and cheetah are regularly spotted, along with rarer species such as fringe-eared oryx, klipspringer, and gerenuk. Birdlife is abundant, too. It's here that some of Kenya's last truly wild black rhinoceros may, with extreme patience, be found. Although you may not experience the density of animal numbers easily spotted on the wide-open plains of the Masai Mara, for example, your encounters will be personal, intimate, and exciting -- unimpeded by crowds and safari traffic.