Millions of years ago, the earth's crust was weakened and tore apart, creating a split thousands of kilometres long down the continent of Africa up to 62 miles (100km) wide in places. Volcanic eruptions on either side caused the floor to sink into a flat plain, creating the Great Rift Valley.
It's one of Kenya's characteristic features and divides the country in half, from north to south, with stunning panoramas and beautiful escarpments. The wide valley is scattered with a few volcanoes and several lakes; it's inhabited by grazing animals, Maasai herders and small-town dwellers.
The string of alkaline lakes known for their stunning scenery and abundant bird life include Lakes Naivasha, Elementaita, Nakuru, Bogoria and Baringo. The uniqueness lies in their high concentration of sodium carbonate from the surrounding volcanic rocks. This creates an ideal breeding ground for algae and a thriving environment for fish, which in turn attracts millions of birds to feed on the abundant food supply. Each of the lakes has a different water composition ranging from freshwater to very saline and brackish, with different birdlife attracted to each.