The Fish River Canyon features a gigantic ravine, in total about 100 miles (160 km) long, up to 27 km wide and in places almost 550 meters deep.  The Fish River is the longest interior river in Namibia.  It cuts deep into the plateau which is today dry, stony and sparsely covered with hardy drought-resistant plants.  The river flows intermittently, usually flooding in late summer; the rest of the year it becomes a chain of long narrow pools.  The hot springs resort of Ai-Ais is situated at the lower end of the Fish River Canyon.