Lake Elementaita Panorama
The cache, a small screw-capped platic tube, is hidden behind some small rocks under a large rock at this great 360 degree viewpoint on the top of a rocky cliff running north-west along the eastern shore of the lake, which is the highest land (1,900m) overlooking the lake (1,775m). The location also gives fine views to the NNE of the ranges of hills rising to 2,700-2,800m. The cliff marks a step fault in the eastern wall of the Great Rift Valley.
To reach the cache: coming from the south (Nairobi), turn off the main A104 Nairobi-Nakuru highway @ S 0 25.937 E 36 15.808 just before the highest point of the road and the hill with the transmission relay mast on top. Follow the higher level dirt trail to the right around the edge of the trees and up to the top of the hill. With a little care the route can be done in a (non-4WD) car - otherwise park somewhere convenient and make the short stroll up the hill by foot. The cache is located in an area about 100m NNW of the mast.
Lake Elementaita was formed around 12 million years ago when the emergence of the Great Rift Valley caused a series of inland drainage basins to be formed. As a result, the rocks of the region are mostly volcanic whilst the soils are fragile, highly porous and highly susceptible to erosion. The ecological balance of the lake is constantly under threat thanks to the drastic fluctuations in water level that occur due to little-understood interactions between hydrology, meteorology and geology. Meanwhile the populations of algae, invertebrates, fish and flamingos can only survive under very specific conditions, which means that any change in water level and/or composition has a drastic impact on the entire biosphere.
For more information on the lake see GC412EC Cole's Ultimate View.
At the time placing the cache the lake, in common with other Rift Valley lakes, was at its highest level for at least 10 years. The dilution of the (sodic alkaline) water has greatly reduced the food source (brine shrimp and blue-green algae) of the numerous (mainly Lesser) flamingos which normally live on the lake forcing them to fly off in search for fodder elsewhere, with far less remaining than for many years.
See here for an interesting research paper on the recent Rift Valley lakes flooding and ecosystem implications.