Menkaure's Pyramid

 was the smallest of the three pyramids of Giza. The First Doctor, Susan, Barbara and Ian materialised in the pyramid in the 26th century B.C., whereupon they were taken to Mankaure's throne room. They later retreated back to the pyramid and dematerialised, after an attempted assasination by Itennu and Kemnebi on the pyramid's namesake Pharaoh Menkaure. (COMIC: The Forgotten)