A publication of the Archaeological Institute of America
The chambers inside the Pyramid of the pharaoh Menkaure (2532-2504 B.C.) at Giza have been closed to visitors for cleaning and repair. Moisture exhaled by tourists had raised the humidity within them to such high levels that salt from the stone was crystallizing and fungus was growing on the walls. Left unchecked, the salt could cause the stone to crack, weakening the structure. A ventilation system may be installed to help keep humidity as low as possible. The pyramids of Cheops and Khafre are already closed for similar work.