Mesopotamia was a very ideal place for creating a civilization.
It is in between two sources of water, the river Tigris and the river Euphrates. Running water is good for food (fish), drink, trade, protection, and travel.
The area was made up of hills and plains. There was plenty of fertile soil, which is good for growing food. This is very important because when the area is good enough that there is a surplus of food, not everybody has to be farmers just to survive. This is how artists, businessmen, merchants etc. flourish.
Finally, the climate was great for farming. There was a warmer season and a rainy season.