La Dune Rose, also called the Dune of Koima, rises across the Niger from Gao and is the city's classic natural viewpoint. The name comes from the colour the sand can take in low light, when dawn or sunset gives the dune a warm pink cast.
The trip is simple in idea and memorable in practice: cross by pirogue, climb the sand, and look back over the river and the flat Sahelian country around Gao. Conditions in northern Mali can change quickly, so this is one to arrange through trusted local contacts rather than improvising on arrival.