The fertile crescent is a fertile region in otherwise dry lands. It stretches, in a crescent form, from what was formerly known as Mesopotamia and the eastern coast of the Mediterranean sea to regions around the Tigris river and the Persian Gulf. It includes regions of Egypt, Iraq, Kuwait, Syria, Lebanon, Israel, Jordan, Turkey and Iran. The main geographic features of this region are rivers, marshlands, fertile areas, desert plateau, snow-covered mountains and tectonic divergence (regions where tectonic plates are moving away from each other). This region lies at the boundaries of African and Arabian tectonic plates. The presence of such divergent climates and geographical features has enabled this region to be very diverse in terms of flora and fauna. The fertile crescent is also known as the cradle of civilization since it served as the base for earlier civilizations (including Mesopotamia), aided by flowing water and fertile soils.
Hope this helps.