The ancient civilization known for building the pyramids is Ancient Egypt. Flourishing along the Nile River, this civilization emerged around 3100 BCE and is renowned for its remarkable architectural achievements, including the construction of the iconic pyramids at Giza. These monumental structures served as royal tombs and were built during the Old Kingdom, primarily for pharaohs who were believed to be divine figures. The pyramids exemplify the Egyptians' architectural ingenuity, ability to mobilize labor, and deep-seated religious beliefs about the afterlife, showcasing their advanced understanding of mathematics and engineering that has fascinated historians and archaeologists for centuries.