Sossusvlei is a salt and clay pan surrounded by high red dunes, located in the southern part of the Namib Desert, in the Namib-Naukluft National Park of Namibia. It is one of the major visitor attractions of the country of Namibia. The oldest dunes are those of a more intense reddish color. These dunes are among the highest in the world; many of them are above 200 meters, the highest being the one nicknamed Big Daddy, about 325 meters high, however the highest dune in the Namib Desert, Dune 7, is about 388 meters high.
The name "Sossusvlei" is of mixed origin and roughly means "dead-end marsh". Vlei is the Afrikaans word for "marsh", while "sossus" is Nama for "no return" or "dead end". Sossusvlei owes this name to the fact that it is an endorheic drainage basin (i.e. a drainage basin without outflows) for the ephemeral Tsauchab River.