The Great Pyramid of Giza, one of the Seven Ancient Wonders of the World, has remained an imposing figure above the Egyptian desert for the better part of the past four and half millennia. It’s a constant among the ever-shifting sands—and on American currency. (Here’s why there’s a pyramid on the dollar bill.) But a recent discovery may have revealed a new structural quirk to one of antiquity’s greatest gifts to humanity.
A new finding published in Nature states that within the Great Pyramid, there is a previously undiscovered inner-chamber to the largest of Giza’s pyramids. The last time a new internal structure was discovered in Egypt’s most famous monument was in the 19th century. The discovery was made thanks to research completed by the ScanPyramids project, which employed muon tomography to non-invasively map the interior of the monument.
Muon tomography is a technique which involves using muons, by-products of cosmic rays, to penetrate through dense layers of matter (in this case, stone) to generate 3-D images of the internal environs. Muon tomography was developed by scientists at the Los Alamos National Laboratory in New Mexico in 2002 in order to better identify nuclear threat materials. Commercially, it’s commonly used to scan shipping containers coming through ports.
The muon scan mapped out a void measuring 100 feet long, seemingly identical to another structure above it, the pyramid’s Grand Gallery. It’s unclear what the hidden chamber was used for at the moment. The Great Pyramid was created to serve as the tomb of the 4th dynasty pharaoh Khufu, who ruled from 2509 to 2483 B.C.E. For more surprising facts about the pyramids and other historical oddities, check out these 19 mid-blowing historical connections you never learned about.