The highlands are divided by the Mulobozi River, which flow into the lake just north of Moba port. The northern section reaches an altitude of while the larger southern part reaches. Mean annual rainfall is around, mostly falling between October and April. The soil is relatively low in nutrients. A sublacustrine swell extends from the Marungu plateau under the southern basin of Lake Tanganyika, subdividing it into the Albertville and Zongwe basins. The Zongwe trough holds the deepest part of the lake, at below the present lake level. Alluvial cones from the rivers that drain the Marungu Plateau are present at the foot of the Zongwe trough, and there are many V-shaped valleys below the lake level. These features indicate that during the Quaternary the lake level varied greatly, at times being much lower than now. The explorer Henry Morton Stanley noted this feature when he visited the region in his journey of 1874–77. He wrote, "Kirungwé Point appears to be a lofty swelling ridge, cut straight through to an unknown depth. There are grounds to believe that this ridge was once a prolongation of the plateau of Marungu, as the rocks are of the same type, and both sides of the lake show similar results of a sudden subsidence without disturbance of the strata."
Ecology
The higher parts of the highlands are Miombo woodland savannas, with scrub plants on the slopes and some dense forest in the ravines, and remains of riparian forest along the streams. Forest plants include Parinari excelsa, Teclea nobilis, Polyscias fulva, Ficus storthophylla and Turrea holstii in ravines, and Syzygium cordatum, Ficalhoa laurifolia and Ilex mitis by the water. Hyperolius nasicus is a small, slender tree frog with a markedly pointed snout, a very poorly known member of the controversial Hyperolius nasutus group. It is known only from its type locality in the Marungu highlands at Kasiki, at. The greater double-collared sunbird is found only in the riparian forest of this area. The sunbird is found in only a few areas of riparian forest. It has been recorded from Kasiki, the Lufoko River, Matafali, Pande and Sambwe. It is one of 25 bird species in Zaire that were considered threatened in 1990. A 1990 book recommended conservation measures in the Highlands focusing on endemic plants. The Marungu Highlands riparian forest patches are in great danger of destruction from logging and from stream bank erosion by cattle. There have been proposals to conserve the forests that border the Mulobozi River and Lufuko River above within nature preserves.
Early reports
Prehistoric stone tools, facies with rare bifaces, have been found in the region dating from the Early Pleistocene to the present Holocene epoch. During that period the climate alternated several times between arid or semi-arid and pluvial. The English explorer Richard Francis Burton visited the region in 1857–59. At that time Marungu was one of the sources of slaves collected by the Arabs and taken to the great slave market at Ujiji. The Watuta had earlier plundered the land and almost wiped out the cattle of the inhabitants. A merchant from Oman who had lived in the region for five months told Burton it was divided into three distinct provinces. There were Marungu to the north, Karungu in the center and Urungu in the south. Burton also heard of a Western Marungu, divided from the eastern by the Runangwa River. Burton was somewhat skeptical about the name, which he thought was more likely that of a race than a country. Burton reported that, Stanley visited Marungu in 1876. He wrote, "Though the mountains of Marungu are steep, rugged, and craggy, the district is surprisingly populous. Through the chasms and great cañons with which the mountains are sometimes cleft, we saw the summits of other high mountains, fully 2500 feet above the lake, occupied by villages, the inhabitants of which, from the inaccessibility of the position they had selected, were evidently harassed by some more powerful tribes to the westward." Joseph Thomson visited the region in 1878–80. He reported that there was no head-chief in Marunga, which was divided into three independent chieftainships that sometimes engaged in warfare. From north to south these were called Movu, Songwe and Masensa. The chiefs were Manda, Songwe and Kapampa. The people were "most excitable and suspicious", and Thomson had difficulty in obtaining permission to travel through the country. Thomson wrote: Thomson said of the terrain, "We had now no gentle undulations and rounded valleys, but savage peaks and precipices, alternating with deep gloomy ravines and glens. Ridge after ridge had to be crossed, rising with precipitous sides, and requiring hands and knees in the ascent. Now we would go up 3000 feet, to descend as far, repeating the process three times a day, and never getting half a mile of moderately good walking ground." He visited during the rainy season, which added to his discomfort. Thomson conceded, "... the savage and awe-inspiring grandeur of the mountain scenery we traversed in Marungu was not without its relief. Here the sun, darting his rays through a rift in the overhanging cloud-bank, would glorify as if with a golden crown some conspicuous peak, or smile upon some pleasant glade; and there glimpses of Tanganyika would be obtained, 2000 feet beneath us, its waters in the distance seeming as calm and undisturbed as the sleep of innocence."
