The Okavango Delta is a huge emerald oasis right in the burning heart of the Kalahari desert. Fed by the Okavango River, and locked in a complex cycle of flood and drought, it is a magnet for people and wildlife in this otherwise parched land. While the Kalahari is battling with the peak of its dry season, the Okavango Delta floods with the waters drained from the summer rains in Angola. It expands threefold, and becomes a sanctuary for life. But the delta is an anomaly: all this water never reaches the sea. Instead it is sucked into the thirsty sands of the Kalahari or evaporates into the atmosphere. And even these vast expanses of watery swamps eventually succumb to the heat of Botswana’s dry season: the delta shrinks once again, making life difficult for its inhabitants. Only when the summer rains eventually return to the delta, does its annual cycle of flood and drought begin again, sending a reprieve to the parched land. This perpetual cycle of wet and dry is the lifeblood of this extraordinary natural Eden.

Namibia - in the south-west of Africa between the Orange river in the south and the Kunene river in the north - is an arid, rough land, a different world. Its treasures are revealed to us, from the speedy cheetah stalking and killing prey, to the territorial beach fights between Cape Cross seals. It’s unique landscapes surprise us, with its mammoth sand dunes, and rocky mountains. This place has been inhabited for thousands of years, by people as well as animals. The Himba people shows us their strong connections to their ancient ancestors through time tested rituals, further documented by stone and cave paintings. Bizarre desert plants and oasis dwelling baboons reinforce this land as a fascinating story of life – and death.

Ngorongoro is thought to have formed about 2.5 million years ago from a large volcano, whose cone collapsed inward after a major eruption, leaving the present vast, unbroken crater as its landmark. This fertile land is full of wildlife, from cunning hyena and proud lions to vast herds of wildebeest and elephants. The hardy Masaai tribe use Lake Natron’s salt to tend their cattle, whilst the world’s largest flock of Flamingo relax in its almost fail-safe breeding grounds.

The wild water of Africa’s Zambezi river spills over Victoria Falls. The local people fully aware of its awesome power dubbed it ‘Mosi-oa-Tunya’ or ‘the Smoke that Thunders’. With a width of 1 mile and a height of 360ft, the Victoria Falls forms the largest sheet of falling water in the world. In the height of the wet season, columns of spray can be seen from 30 miles away, as 546 million cubic meters of water per minute plummet over the edge. The Zambezi is traversed several times one of the world’s most epic natural events: the wildebeest migration.

The longest river in the world at 6,700km (4,160 miles), the Nile drains over 3 million km² (1.5 million square miles), or 10% of Africa. Some of its water takes six months to reach the sea. Though it flows through one of Earth's harshest deserts and travels the last 2,400km (1,500 miles) without a single tributary, it never runs dry. The Sudd is one of the largest swamps in the world covering 32,000km² (1,2355 square miles). Silt and marsh sediments are thought to be an astonishing 10km (6 miles) deep. A labyrinth of floating papyrus islands, it supports enormous numbers of fish.

Virunga National Park is notable for its chain of active volcanoes and the greatest diversity of habitats of any park in Africa: from steppes, savannas and lava plains, swamps, lowland and forests, to the icefields of the Ruwenzori mountains, which culminate in peaks above 5000m. The great diversity of habitats harbors an exceptional biodiversity, including endemic as well as rare and globally endangered species, such as the mountain gorilla. The Ruwenzori or 'Mountains of the Moon', sit between the humid forests of the Congo Basin and the monsoon lands of East Africa. The Ruwenzori's glaciers, frozen at some 5,000m (16,500ft) above sea level drip feed bogs which in turn feed mountain streams, rivers and the great African lakes of Victoria, Albert, Edward and George.

Madagascar is the world’s fourth largest island and is separated from Africa by hundreds of kilometres of sea and 165 million years of evolution – long enough for Madagascar’s plants and animals to evolve into some of the weirdest forms on the planet. Nowhere else can you see over 70 varieties of lemur, including one that sounds like a police siren, the world’s biggest and smallest chameleons, and the last stomping ground of the elephant bird, the largest bird that ever lived. And the plant life is even stranger: Forests of twisted, spiny ‘octopus’ trees, bottle-shaped baobabs, and the carnivorous pitcher plant

Kilimanjaro is the tallest free-standing mountain rise in the world, rising 4,600 metres (15,000 ft) from its base, and is the highest peak in Africa at 5,895 metres (19,340 ft), providing a dramatic view from the surrounding plains. Nestling in its foothills is Tsavo National Park. Tsavo boasts volcanic hills, four rivers, more than 60 major mammal species and 1000 plant species. The area is known for its herds of ‘red elephants’, their skins stained by the local ochre dust. The nearby volcanic hills hold the key to one of the most precious ecosystems in Africa: Mzima Springs, where a gushing supply of fresh, crystal clear water has created an oasis for wildlife. It is home to several pods of hippo, crocs and shoals of barbell and catfish.

Lake Tanganyika is the longest lake in the world stretching 660km north to south. It is also the second deepest freshwater lake reaching a maximum depth of 1,436m (4,711ft)/ It is a staggering geological feature, a flooded rift valley occupying the southern end of the Western Rift Valley and forming the boundary between Tanzania and Congo (Kinshasa). Lake Tanganyika is less of a lake and more like an inland sea. Even the creatures found here seem like ocean species: sponges, crabs, jellyfish. The lake's sheer size - and the length of time it's been isolated from the outside world - have led to the evolution of creatures such as Limnonida - similar to ocean jellyfish, yet totally unrelated.

The 'dark heart of Africa' is really a beautiful, bright wilderness. At its heart lies the world's second largest river system - the Congo River. The Congo River system drains an area the size of Europe fed by ten thousand streams. This rich and vast jungle is home to an incredible diversity of wildlife. Open patches in the midst of the forest - called bais - have been a major discovery here. Some are simple arenas of grass. Others, like Wali bai, contain streams or pools. The bais brim with life, as forest creatures home in on these oases of light in the midst of darkness. The bais attract large mammals out of the forest. Even the least known of the Congo primates, the western lowland gorilla.

The Sahara, with a size of 8.6 million km², is the world's largest desert, covering more than 25 per cent of Africa. About a quarter of the Sahara consists of mountains. The highest peak reaches 3415, being Emi Koussi in Chad. Some mountain peaks may even have snow in the winter. The Grand Erg Oriental (Eastern Sand Sea) and the Grand Erg Occidental (Western Sand Sea) are just two of about 20 such Saharan sand seas whose sands in some areas reach over 300m deep. Ergs have large areas of actively shifting as well as fossilised dunes. Despite the extreme aridity, the Sahara is home to some surprising wildlife.

This is the largest delta in Africa where the Niger River meets the sea. Covering 36,260km², it's nearly twice the size of Ireland. Nearly 20 mouths reach the sea here. The two main ones are the Nun and the Forcados. The outer delta is fronted by a zone of sandy beaches backed by mangrove swamps and creeks. Inland, towards the head of the delta the vegetation changes to freshwater swamps and dense forest. In central Mali, the Niger forms a vast inland delta, a maze of channels and shallow lakes.The river continues through the Republic of Niger and on into Nigeria where it is joined by its chief tributary, the Benue. The Niger then proceeds south 400km before becoming a great fan-shaped delta and emptying into the Gulf of Guinea.

The Ethiopian Highlands are a rugged mass of mountains in Ethiopia, Eritrea and northern Somalia in the Horn of Africa. They form the largest continuous area of its altitude in the whole continent, with little of its surface falling below 1500 m (5000 ft), while the summits reach heights of up to 4550 m (15,000 ft). It is sometimes called the Roof of Africa for its height and large area it covers. The Ethiopian highlands first began to rise 75 million years ago, pushed upwards by volcanic forces. The main dome was split into two halves, the northern and southern highlands, by the development of the Great Rift Valley. Plants and animals from different directions then colonized these separate massifs.