In Mesopotamia, the land is very fertile. In the Northern part of Mesopotamia, there are rivers and streams that are fed from the mountains. In addition, there is a rainy season that helps water the soil. While the southern region is much hotter and dryer, the two large rivers the Tigris and the Euphrates, allow irrigation. The land between the rivers was filled with wildlife and edible vegetation making it an attractive area for early man to move in to. Once they figured out how to grow crops there, civilization soon followed.