The Democratic Republic of the Congo holds five UNESCO World Heritage natural sites. No other African country has more. Virunga National Park, established in 1925, is the continent's oldest national park. Salonga National Park covers 33,350 square kilometers, making it the largest tropical rainforest reserve in Africa. Kahuzi-Biéga National Park protects one of the two remaining populations of eastern lowland gorillas, a subspecies found nowhere else on Earth. The Okapi Wildlife Reserve is the only significant habitat for the okapi, a forest giraffe relative discovered by Western science in 1901. Garamba National Park, though severely pressured, remains on the World Heritage list. These five sites exist because the Congo Basin rainforest is the world's second largest rainforest after the Amazon, and the DRC contains roughly 60 percent of that basin.
Lake Tanganyika forms much of the DRC's eastern border. At 1,470 meters deep, it is the second deepest lake on Earth after Lake Baikal. It holds roughly 16 percent of the planet's available freshwater. More than 350 fish species inhabit the lake, with cichlid endemism near 98 percent. The DRC's lakeshore provinces of South Kivu and Tanganyika provide access to this water body, though tourist infrastructure around Uvira and other lakeside towns remains minimal.
The Congo River is the world's deepest river, reaching depths exceeding 220 meters in certain canyons near Kinshasa. It is the second longest river in Africa at approximately 4,700 kilometers, after the Nile. The river discharges roughly 41,000 cubic meters per second into the Atlantic, second globally only to the Amazon. Inga Falls, located 225 kilometers southwest of Kinshasa, is not a single waterfall but a series of rapids dropping 96 meters over 15 kilometers. The potential hydroelectric capacity at Inga is estimated at 40,000 megawatts, which would make it the largest hydroelectric installation on Earth if fully developed. Current infrastructure captures a small fraction of this.
Boyoma Falls, formerly Stanley Falls, comprises seven cataracts stretching 100 kilometers along the Lualaba River near Kisangani. The total drop is roughly 61 meters. Livingstone Falls is a series of rapids and cascades where the Congo River drops 270 meters over 350 kilometers between Kinshasa and Matadi. These falls make the Congo unnavigable between the interior river network and the sea, a geographic fact that has shaped settlement patterns and economic geography since precolonial times.
Virunga National Park covers 7,800 square kilometers. The park spans lowland rainforest, Albertine Rift montane forests, savannas, lava plains, swamps, and glaciated peaks. Mount Nyiragongo, within the park boundary, contains the world's largest lava lake. The lake measured approximately 700 meters across during observations in the 2000s. Nyiragongo erupted in January 2002, destroying 13 percent of Goma and displacing 120,000 people. The lava flowed at speeds up to 60 kilometers per hour, one of the fastest recorded lava flows. The volcano remains continuously active. Approximately 300 mountain gorillas live in the Virunga Massif, split among Uganda, Rwanda, and the DRC. The DRC portion hosts roughly one-third of this population.
Kahuzi-Biéga National Park is named after Mount Kahuzi at 3,308 meters and Mount Biéga at 2,790 meters. The park was established in 1970 and expanded in 1975 to 6,000 square kilometers. The park contains the largest remaining population of eastern lowland gorillas, scientifically named Grauer's gorillas. Population estimates in the 1990s exceeded 16,000 individuals. Surveys in the mid-2000s suggested fewer than 5,000 remained. Current numbers are difficult to verify due to limited access in sections of the park. This gorilla subspecies is the world's largest primate by body mass, with adult males exceeding 200 kilograms.
Salonga National Park is divided into northern and southern sectors separated by roughly 45 kilometers of inhabited land. Total area is 33,350 square kilometers. The park is accessible only by air or by river, with no roads penetrating the interior. Forest elephants, bonobos, Congo peacocks, and African slender-snouted crocodiles inhabit the park. The bonobo, Pan paniscus, is found only in the DRC, entirely south of the Congo River. Total wild population estimates range between 15,000 and 20,000 individuals. Salonga contains a significant fraction of that population, though exact numbers are unknown.