34.0942°N, 123.2008°E.
Saline lake on Middle Island in the Recherche Archipelago off Western Australia. The lake is approximately 600 metres long and 250 metres wide, separated from the Southern Ocean by a narrow band of eucalypt-covered dunes. The water is bubblegum-pink year-round at high salinity (10× seawater); the color is produced primarily by the halophilic alga Dunaliella salina which produces β-carotene under salt stress, with secondary contributions from the bacterial archaeon Salinibacter ruber and the bacterium Dechloromonas aromatica. The pink color persists when water is removed from the lake, eliminating optical effects of the lakebed as a cause. First documented by British navigator Matthew Flinders in 1802. There are at least 11 other pink lakes on Earth; Lake Hillier is the most consistently pink and the densest in pigment.
A 600-metre lake is a different color than the ocean it borders — because the algae living in it have to manufacture pigment to survive their own salt.