Lake Hillier, is a lake on Middle Island, the largest of the islands and islets that make up the Recherche Archipelago, Western Australia. It is the most prominent lacustrine feature on any island of the archipelago and air passengers often take note of it. The specialty of this lake is its flamboyant color, rose pink. The color is permanent, as it does not alter when the water is taken in a container. The length of the lake is about six hundred meters.