Mesopotamia was between two rivers, that caused for the abundance of their crops. The annual flooding of these rivers helped the deposition of silts that are fertile over their crops making it healthy and low maintenance. This in turn allowed them to focus on other things such as art, building, religion etc. Because of the unprecedented of the flooding form two rivers, they made a conclusion that the Gods are so unpredictable and gives a once in a lifetime blessing for their people and so they treasure it dearly y calling it the Fertile Crescent.