Some 20 million years ago, the earth's crust weakened and tore apart creating a jagged rift, thousands of kilometers long, across the African continent. The land on either side erupted creating great volcanic mountains, while the valley floor gradually sank into a low flat plain. This geologic phenomena, dubbed the Great Rift Valley has two branches, the eastern one divides Kenya neatly down the length of the country essentially separating east from west, and continuing south in Tanzania. Whilst the western branch cuts through Uganda and into Tanzanaia. Today's Rift Valley is characterized by uninhabitable desert and fertile farmland, flat arid plains and steep escarpments. Subterranean movement is common today as the Rift Valley is home to thirty active and semi-active volcanoes and countless hot springs along its length. This string of alkaline lakes and boiling springs northwest of Nairobi includes Lake Baringo, Lake Bogoria, Lake Nakuru, Lake Elementaita, Lake Naivasha, and Lake Magadi in the south and Lake Natron in northern Tanzania. These lakes are unique because their water is highly concentrated sodium carbonate. This situation is caused by the high alkalinity from the surrounding volcanic rocks coupled with poor drainage outlets due to the steep sides of the valley. The high evaporation of the surface lake water results in sodium carbonate which, in turn, creates an ideal breeding ground for algae. Several species of fish, tilapia in particular, thrive in this environment. As a result, millions of birds flock to these soda lakes to feast on the abundant food supply of algae and fish. Each of the lakes in the Rift Valley string have a slightly different water composition ranging from freshwater to extremely alkaline, highly saline to brackish. The lakes in the western branch are the Edward, Albert, and southwards to Lake Kivu and Tanganiyka, the second deepest lake in the world. These lake are all fresh water.

Gilgil is a small town on the edge of the Great Rift Valley, between Naivasha and Nakuru. The Malewa river flows down from the Aberdare Range and on into Lake Naivasha. This river has trout in it.
Close by is Lake Elementaita, a soda lake which is a haven for many resident and migrant birds, and seasonal home to flocks of Flamingo. There is a pre-historic site at Kariandusi.

The Cherangani Hills are situated in Northwestern Kenya, on the edge of the Great Rift Valley, overlooking the Lake Turkana Basin. The hills are home ot the Pokot people.
The bird life here is spectacular, there is execllent trekking and walking and the streams offer some trout fishing.

The Nguruman Escarpment is an escarpment in southern Kenya, approximately 120 km south of Nairobi. It forms the western wall of the Great Rift Valley. Below it are the vast plains and the volcanic hills of the Great Rift Valley and in the distance are Lake Magadi and Lake Natron. To the west are the Loita plains, leading on to the Masai Mara.

Limuru is a town located on the eastern edge of the Great Rift Valley about 30 miles North-West from Nairobi, the capital city of Kenya. Limuru residents rely mostly on farming and a shoe factory for employment. Early in the British colonial period (from the 1890s) Europeans settled in the area due to its proximity to Nairobi, the railway, its fertile land and pleasant weather. The tea plantations established around Limuru from 1903 onwards were the foundation of Kenya's largest export industry, which produces some of the world's highest quality tea.

Kapiti plains consist of open grasslands to the south and southwest of Nairobi.

Rongai is an agricultural area on the western edge of the Great Rift Valley, overlooking Lake Nakuru and Menengai volcano.

Laikipia District is a vast plateau in central Kenya covering an area of approximately 2 million acres. The plains stretch from the Great Rift Valley and the Aberdare Mountains in the west to the magnificent escarpments, which descend into the Northern Frontier districts. Laikipia is unique because its wildlife numbers have increased over the last two decades. It is home to over 2000 elephants - Kenya's largest population outside the National Parks and Reserves. They are still free to undertake a seasonal migration that takes them more than 100 kilometers north into the Samburu rangelands during the rainy season. Laikipia is also one of the last refuges for the black rhino, with ranchers setting up five heavily protected rhino sanctuaries, which now hold the majority of Kenya rhino. The District also provides a haven for Grevy's Zebra, and about 25% of the world's population of this species is believed to live in Laikipia. Other species include common zebra, oryx, eland, buffalo and reticulated giraffe while predators include cheetah, lion, leopard and wild dog. This combination of abundant wildlife and beautiful scenery has encouraged Laikipia to become the centre of new developments in high quality tourism and, in addition to this, has developed the most advanced community conservation and wildlife management programme outside of Kenya's protected areas.

Location

Mweiga is the area to the north east of the Aberdare mountain range, on the edge of the Laikipia plateau.