In the middle of the third millennium BC, about 2631 BC to 2498 BC. In Giza, in the Nile Delta, three great pyramids were created, consisting of the three emperors of the fourth dynasty, Khufu, Khafra, and Menkaura, in 2600 BC. Built in 2500 BC. It is the most mature representative of the ancient Egyptian pyramids, which is the big pyramid we now often say. In the suburbs of today's Cairo, it is mainly composed of the Great Pyramid (also known as Khufu), Khafra, and the Menkaura Pyramid ( Menkaura) and the Great Sphinx. There are also many Mastaba and small pyramids around.