The ancient civilization that built the Pyramids of Giza was Ancient Egypt. These monumental structures were erected during the Fourth Dynasty of the Old Kingdom, around 2580–2560 BCE. The Great Pyramid of Giza, built for Pharaoh Khufu, is the largest and most famous of these structures. They served as elaborate tombs for the pharaohs, reflecting their immense power and religious beliefs in the afterlife. The construction of the pyramids is a remarkable feat of engineering, demonstrating the advanced skills and organization of the Egyptian society at that time.