Located on Middle Island, which forms part of the Recherche Archipelago off the southern coast of Western Australia, Lake Hiller is a fascinating bright pink lake that has to be seen to be believed. The color of the lake is thought to be caused by a high salt content combined with the presence of a special species of algae, but this has not been conclusively proved. The best way to see this freak of nature is on a helicopter tour or a boat cruise, both of which are available from the coastal town on Esperance, which is a stop along the famous Great Ocean Drive. Unfortunately, the lake itself is off-limits to visitors but the remainder of the Recherche Archipelago offers amazing opportunities for swimming, snorkeling, and scuba diving.