Mesopotamia, meaning "between two rivers" in Greek, was located between the Tigris and Euphrates Rivers in an area known as the Fertile Crescent. Around 12,000 years ago, hunter-gatherers began settling in Mesopotamia and by 7,000 BC had started farming wheat, barley and livestock. To control floods and drought, they developed irrigation systems like canals. This led to food surpluses and the rise of cities between 4,000-3,000 BC where trade and culture flourished, though agriculture remained the main activity.