(Persian: “country of sand”), arid plateau region in southwestern Afghanistan. Rīgestān is, for the greater part, a sandy desert with ridges and small, isolated hills of red sand. The sand ridges and dunes, reaching heights of between 50 and 100 feet (15 and 30 m), alternate with windblown sand-covered planes, devoid of vegetation and changing in some parts into barren gravel and clay. In the local language the Rīgestān is often called the chol (“desert”). Some gypsum is mined at Galeh Chad, and Baluchi and Pashtun nomads, herders of sheep, goats, and camels, use portions of the Rīgestān near the Helmand and Arghandab rivers as winter pasture.