Ergs are mostly covered with dunes, but there are also some where dunes are absent. Many of the dunes found in the Sahara are more than 180 meters high.
The highest dunes in the Sahara are found in a desert with the sonorous name Isaouane-n-Tifernine in Algeria. The height of the dunes ranges from 420 to 465 meters (1377 to 1525 feet) . The dunes of Isaouane-n-Tifernine are considered the fifth highest dunes on earth.
