Assist. Lecturer: Eng. Ingham Salim Mohammed Clay is considered one of the most fundamental materials upon which the civilization of Mesopotamia was built. It was directly linked to the emergence of urban life in ancient Iraq and left its mark on writing, architecture, and all aspects of daily activities. Clay is frequently mentioned in cuneiform sources in both Sumerian and Akkadian languages, reflecting its deep presence in the cultural consciousness of ancient people. In Sumerian, clay was referred to by the term IM, while in Akkadian it was known as ṭīṭu, a comprehensive term denoting clay as a basic raw material used in various fields of life. It was not merely a natural substance, but an essential part of the economic and cognitive structure of ancient Iraqi society. It was used in the production of cuneiform tablets on which administrative, religious, and legal texts were written—texts that preserved the details of daily life in the ancient cities of Iraq. Clay was also used in the manufacture of pottery, seals, cylinder seals, figurines, and tablets, in addition to its use in producing mud bricks (adobe) and baked bricks, which formed the primary material for constructing houses, temples, and city walls. In the architectural aspect, clay formed the foundation of ancient Iraqi buildings, where Mesopotamian civilizations relied on simple yet effective techniques based on sun-dried bricks or occasionally fired bricks to increase their strength. This type of construction enabled humans to adapt to the local environment characterized by hot and dry climate conditions, as clay provides natural thermal insulation that helps maintain moderate temperatures inside buildings. Therefore, mud architecture was not merely a technical choice, but an intelligent environmental response reflecting the ancient human’s understanding of their surroundings. Over time, these buildings have become an essential part of Iraq’s tangible heritage, studied and preserved by archaeology specialists. They are regarded as material historical documents that reflect the development of architectural, social, and economic thought of ancient civilizations, rather than being mere archaeological remains. The sustainability of mud-brick buildings requires precise scientific efforts to protect them from natural and human-induced deterioration factors such as humidity, erosion, and urban expansion. Archaeologists rely on modern methods in this regard, including digital documentation, 3D scanning, and the use of restoration materials compatible with the original clay to ensure the preservation of the archaeological structure without distortion. International organizations such as UNESCO also play an important role in supporting heritage preservation projects. The importance of clay does not lie only in being an ancient building material, but in being a comprehensive cultural element that combines knowledge, architecture, and identity. Today, the sustainability of mud buildings means preserving Iraq’s historical memory and keeping the material evidence of a civilization that represents one of the most important pillars of human history alive. Therefore, preserving this heritage is not merely an archaeological task, but a cultural and humanitarian responsibility to ensure the continuity of the relationship between the past, present, and future #AlMustaqbal_University_First_Among_Private_Universities_in_Iraq