Lake Retba is the pink, highly saline lake in Senegal commonly known as Lac Rose. Its vivid colour is associated with salt-loving microorganisms, especially the algae Dunaliella salina, whose reddish pigments become more prominent in intense sunlight and concentrated salt water.
The shallow lake lies near Senegal’s Cap-Vert Peninsula, northeast of Dakar, and is separated from the Atlantic Ocean by a narrow band of dunes. During the dry season, evaporation can push salinity to extremely high levels—up to about 40 percent in some parts—allowing people to float easily, much like in the Dead Sea.
Lake Retba is also an important working landscape. Salt collectors gather deposits from the lakebed and load them into wooden boats; the salt is used locally, including for preserving fish. The lake was famous internationally as the traditional finish of the Dakar Rally before the event moved away from Senegal in 2009. Its colour is not permanent: heavy rains and flooding can dilute the water and temporarily turn it less pink.