This large shallow lake lies at 4,278m a.s.l. in the southwestern part of the altiplano in Bolivia near the border with Chile. The colour is due to the microscopic activities of algae and other organisms that thrive in the lake which also provide an important source of food for migrating Flamingos in this otherwise barren landscape. The colour is fading near the shore as it is shallowest and hence cools quicker than the deeper part in the centre where the temperature is still optimal for the organisms to remain active. By dusk, the red colour would be completely gone.