Dasht-e Kavir (Central Desert), also known as Kavir-e Namak or Great Salt Desert is a large desert lying in the middle of Iranian Plateau. It is about 800 kilometers (497 mi) long and 320 kilometers (198 mi) wide with a total surface area of about 77,600 km² (~30,000 mi²).The area of this desert stretches from the south hillside of Alborz mountain range in the north-west to Dasht-e Lut (“Emptiness Desert”) in the south-east and is partitioned between the Iranian provinces of Khorasan, Semnan, Tehran, Isfahan and Yazd. It is named after the salt marshes (Kavir) located there.The Dasht-e Kavir’s climate is almost rainless and the area is very arid.Temperatures can reach 50 °C in summer, and the average temperature in January is 22 °C. Day and night temperatures during a year can differ up to 70 °C. Rain usually falls in winter. Among the driest places on the planet, it receives an average of only 1.2 inches (3 centimeters) of rain a year. Certain areas of the desert reportedly receive no rain. Extremely barren, the desert contains the only region free from any life, including the existence of bacteria, on Earth!