Ruaha is the country's largest national park, following the recent incorporation of several adjoining game reserves to double its original area to 20,540 sq. km (8,011 sq. miles). It has the wildest and most rugged feel of any Tanzanian safari destination, all semi-arid rocky slopes and baobab-studded plains, a harshly beautiful landscape alleviated by the near-perennial Great Ruaha River, which follows the park's southeast boundary for 160km (99 miles), and several small seasonal tributaries. Ruaha also offers some of the finest game viewing in the region, with large concentrations of wildlife -- elephants, in particular -- complemented by low tourist volumes by comparison even to Selous.
Ruaha vies with the Serengeti when it comes to large predators. Lion prides containing more than 15 individuals are a feature of the park, and leopards and cheetah are regularly seen and are generally habituated to vehicles. The park also forms the core territory for an estimated 100 African wild dogs, and though the movements of these wide-ranging animals are unpredictable, at least one pack regularly moves into the Mwagusi area; sightings are especially good in denning season in June and July. Other common carnivores include black-backed jackal and spotted hyena, and the park lies at the southern extreme of the range of the uncommon striped hyena. An estimated 12,000 elephants inhabit the greater Ruaha ecosystem, and the heftiest pair of tusks recorded in the 20th century, with a combined weight 201kg (443 lbs.), came from an individual shot in Ruaha in the 1970s.
In ecological terms, the vegetation is transitional between the southern miombo woodland and eastern savannah biomes, leading to a great floral variety reflected in the varied wildlife. It lies at the southernmost range of typical East African ungulates such as lesser kudu and Grant's gazelle, but it also hosts several species that are rare farther north, including greater kudu, roan, and sable antelope. A similar dichotomy is noted among the 450 recorded bird species, with north-central Tanzania endemics such as black-collared lovebird, ashy starling, and Tanzania red-billed hornbill occurring alongside typical southern African species such as the perpetually trilling (and very colorful) crested barbet.
Visitors driving to Ruaha might want to explore two sites of interest close to Iringa. The first is the Isimila Stone Age Site (entrance around $3), where a seasonal watercourse cuts through sedimentary layers deposited on the bed of a shallow lake over several thousand years before it dried out around 60,000 years ago. The site has yielded one of the world's richest assemblages of Acheulean hand axes and other stone tools, along with the fossilized bones of several extinct large mammals, including a gigantic pig, a giraffe-like ungulate with large antlers, and a hippo with telescoped projecting eyes. The site museum houses a varied selection of these finds, while nearby a scenic gully hosts several magnificently eroded sandstone pillars up to 10m (33 ft.) high.
The more recent past is evoked at the small village of Kalenga, set on the banks of the Ruaha along the road between Iringa and Ruaha. This was once the fortified capital of King Mkwawa, the Hehe leader who acquired legendary status in the late 19th century for his concerted resistance to German rule. Kalenga was razed by German cannon fire in 1894, but Mkwawa stayed on the loose for another 4 years, inflicting occasional guerrilla attacks on the Germans until June 1898, when his camp was surrounded by a German garrison and he shot himself in the head rather than being taken captive. Today a small site museum in the village houses several of Mkwawa's personal effects, including some of his clubs, spears, and guns, and the village is scattered with relics of Mkwawa's rule, including the remains of fortified walls and the foundations of his house. About 1/2km (.3 miles) from the museum is the tomb of the German Commander Erich Maas, who died in the battle of Kalenga.