The study of past civilizations, the history of how they are shaped, and what has changed during the formation has always been a concern. It has existed since the oldest civilization, and some of the buildings have been particularly important during the formation of civilization. Among these are religious buildings which were constructed in order to gather together and create spiritual and religious spaces. It can be said that they were considered as some of the most important buildings because the foundation of culture and the execution of any order and the conduct of any ceremony and the adoption of important decisions were usually taken in these buildings. The book is based on the study of the religious buildings that were formed in Mesopotamian civilization. According to ancient scholars, Mesopotamia is one of the important areas for the establishment of ancient cultures and civilizations, such as Sumer, Babylonia, Akkad, and Assyria.