Kavīr Desert, Persian Dasht-e Kavīr, also spelled Dasht-i Kavīr, great salt desert of north-central Iran. Located in a basin southeast of the Elburz Mountains, it is approximately 240 miles (390 km) wide. The desert is distinguished by its salt crust, caused by the almost rainless climate and intense surface evaporation, lying over treacherous quicksandlike salt marshes that are almost uninhabited. Settlements are found only in the surrounding mountain ranges.
Lūt Desert, Persian Dasht-e Lūt, also spelled Dasht-i Lūt, desert in eastern Iran. It stretches about 200 miles (320 km) from northwest to southeast and is about 100 miles (160 km) wide. In the east rises a great massif of dunes and sand, while in the west an extensive area of high ridges is separated by wind-swept corridors. In its lowest, salt-filled depression—less than 1,000 feet (300 metres) above sea level—the summer heat and low humidity are believed to be unsurpassed anywhere.