Lake Hillier- Pink lake in Australia

Lake Hillier is a pink-coloured lake on Middle Island in Western Australia. Middle island is the largest of the islands and islets that make up the Recherche Archipelago, a group of about 105 islands and over 1,200 ‘obstacles to shipping’.

The island and lake are thought to have been first charted by the Flinders expedition in 1802. Captain Flinders is said to have observed the pink lake after ascending the island's peak. John Thistle, the ship's master, collected some of the lake's water, which he found to be saturated with salt.Although the source of the pink colour has not been definitively proven in the case of Lake Hillier, the pink color of other salt lakes (e.g., Pink Lake) in the region arises from a dye created by the organisms Dunaliella salina and Halobacteria. Another hypothesis is that the pink color is due to red halophilic bacteria in the salt crusts.
The tiny lake only spans about 600 meters wide but its rose pink color is unmistakable. However, the reason why it’s pink remains a mystery. There is another lake in Africa called Lake Retba  lake as this lake