Seven corbelled courses of stone form the ceiling of the Grand Gallery in the Great Pyramid of Giza.
The Grand Gallery is the steep, sloping passage inside Khufu’s pyramid that leads toward the King’s Chamber. Its walls begin wide at the base and step inward seven times, with each higher course projecting slightly farther over the passage below. This corbelling narrows the upper part of the gallery while creating its distinctive towering appearance.
The gallery extends from roughly the 23rd to the 48th course of the pyramid and rises about 21 metres. Its polished limestone walls are approximately 8.6 metres high and 46.7 metres long. The ceiling itself is made from large stone slabs laid at a slightly steeper angle than the floor.
A common mix-up is to count the gallery’s roof slabs rather than its seven inward-stepping wall courses. The corbelled design also had a structural purpose: it helped distribute the enormous weight above and prevented the roof from relying on a simple stack of blocks. Nearby slots and niches may have helped manage blocking stones, though their exact function remains debated.