The Great Pyramid looks like it has four flat faces, but each one is subtly dished inwards down the middle, making it secretly eight-sided — a detail so slight it was really only spotted from the air, in a photograph caught at the right angle of sunlight. - Space Daily

What the report says

Space Daily reports that the Great Pyramid of Giza, commonly pictured as a four-faced monument, has a more complex surviving exterior: the exposed core masonry on each side includes a recessed area running roughly down the middle. Under low, angled sunlight, those recesses can divide the faces into light and shadow, creating the impression of an eight-sided pyramid.

The article emphasizes that this does not necessarily mean the pyramid was originally built with eight precise faces. The monument was once covered in smooth limestone casing, and Space Daily notes that surviving casing stones along the north base support the view that the finished exterior presented flat faces. Most of that outer stone was later removed, leaving weathered core blocks that are harder to interpret from ground level.

The feature was described by surveyor and archaeologist W. M. Flinders Petrie in an 1883 study, but Space Daily says it became famous after a 1926 aerial photograph taken by British Royal Air Force officer P. R. C. Groves near sunset around the autumnal equinox. More recent scholarship remains divided. The article cites Akio Kato’s 2023 argument that the concavity may reflect a structural method, while Egyptologist Franck Monnier’s 2022 review, using laser scanning and photogrammetry, found irregular patterns that he linked instead to casing removal, damage and weathering.

The significance is that a striking visual claim about one of the world’s best-known monuments rests on a narrower point: the pyramid’s current core can look eight-sided in the right light, but the original design and cause of the grooves remain debated.