Mesopotamian architecture, developed in the ancient region between the Tigris and Euphrates rivers (modern-day Iraq), is one of the earliest forms of monumental building. Known for its use of sun-dried and fired mud bricks, Mesopotamian architecture includes massive ziggurats (stepped temple towers), palaces, and city walls. Structures often featured buttresses, pilasters, and decorative facades with niches and cone mosaics. Religious and civic buildings were central to city planning, reflecting the society's theocratic nature. Innovations such as the arch and vault were also pioneered in this region, influencing later architectural traditions.