Central Asia is a vast region located in inner Eurasia with varied climates and topography. It lacks clear borders or demarcation lines. The population of over 61 million people includes both settled groups in oases and valleys as well as nomadic groups in deserts and steppes. Some of the key geographic facts about Central Asia are that it covers an area of 4 million square kilometers, has over 12,000 km of land borders with neighboring countries, and contains 3,662 km of coastline along the Caspian Sea.