Sossusvlei is a salt and clay pan surrounded by high red sand dunes, located in the southern part of the Namib Desert, in the Namib-Naukluft National Park of Namibia. The dunes reach a height of 300 meters, the highest in the world. The Vlei is mostly dry, sometimes it fills with water that reaches the Vlei through the Tsauchab River. The starting point for the 65-kilometer access road to Sossusvlei is the gateway to the Namib Naukluft Park at Sesriem. The access road has a permanent surface and is suitable for sedan cars, whereas the last 5-kilometere stretch of sandy track is only accessible by 4x4. Other attractions include the Dead Vlei, Hidden Vlei, Dune 45, the Elim Dune and the Sesriem Canyon. The Tsauchab River flows through the Sesriem Canyon, where the erosion of many centuries has incised a narrow gorge of about 1 km in length and 30 meters deep.