Mesopotamia gave us ziggurats. ziggurats were massive structures built in the ancient Mesopotamian valley and western Iranian plateau, having the form of a terraced step pyramid of successively receding stories or levels.
This is an example of a ziggurat located in ancient Mesopotamia. They had many functions. The top of them was a place to worship gods and they were the beginning of public buildings when civilizations were being created. (Comment by original pinner.