In Mesopotamia (modern-day Iraq), the Sumerian civilization developed and built the world's first cities such as Ur and Uruk.
In ancient Egypt, the Old Kingdom period started with numerous advancements in societal structures, arts, and engineering, including the construction of the Giza pyramids.
The Indus Valley Civilization flourished in the basins of the Indus River in present-day Pakistan and India.
In Mesoamerica, the Olmec civilization emerged along the Gulf coast of present-day Mexico.