The Origins of Pyramid Building

Snefru may have been an example of a pharaoh who went pyramid crazy. His pyramids at Madam and Dasher were built with the assistance of his own vizier Nefamart. It is very likely that the responsibility for the organisation of the project would have fallen on the shoulders of Hemiyunu. Currently it is possible to enter the Great Pyramid of Giza and access the internal chambers. However this wasn't originally the intention the entrance would have been sealed off. The entrance that we see today was constructed in the 9th century CE by the Abbasid caliph called Al-Mamun  who was simply entering the pyramid to discover its secrets.