Lake Natron, Tanzania
The Serengeti Plain of Tanzania and Kenya dominate this image of Southeastern Africa. The savanna (grassland with sparse trees) region is renowned for its biological diversity, especially the so-called "big five": elephants, lions, leopards, rhinos, and Cape buffalo.
Some of the oldest fossils of early humans are also found in this area. On the right side of the image, just below Tanzania's border with Kenya, lies Lake Natron (an oblong red splotch roughly oriented north to south). The unusual coloration is due to the presence of microorganisms that feed on the salts that accumulate on the lake surface and the surrounding mud flats.
Spirulina, a blue-green algae that produces red pigments, thrives in this area, and is consumed by the several million flamingoes that inhabit the region, giving them their red color. By some standards -- temperatures exceeding 50 degrees Celsius (122 degrees Fahrenheit) and pH values of 9 to 10.5 (almost as alkaline or basic as ammonia) - the area would be considered inhospitable.
However, these conditions do not seem to bother the flamingoes, nor do they dissuade an endemic species of tilapia from inhabiting the waters at the edges of hotspring inlets. Amazingly, life has adapted to these seemingly harsh conditions, forming a unique community of hardy species.