The ancient civilization known for building the pyramids is Ancient Egypt. The most famous pyramids, such as the Great Pyramid of Giza, were constructed as tombs for pharaohs during the Old Kingdom period, around 2580 to 2560 BC. These monumental structures reflect the Egyptians' advanced architectural skills and their belief in the afterlife, as they were designed to facilitate the pharaoh's journey after death. The construction of the pyramids utilized a workforce of skilled laborers, and they were built using large limestone and granite blocks, demonstrating the civilization's remarkable engineering capabilities.