Sossusvlei is a depression lined by some of the highest dunes in the world. Although a very rare occurrence, during periods of good rains the pan or "vlei" fills up with water from the Tsauchab River. This water wonder in the middle of the desert is a spectacular sight.
At the entry to Sossusvlei is Sesriem Canyon. As a result of erosion over many centuries, a narrow gorge of about one kilometre in length was formed about 30 to 40 metres deep. Early explorers had to tie six lengths of thongs together to draw water from the pools in the canyon, hence the name "Sesriem".