The cavity is the first major inner structure discovered in the pyramid since the 1800s.
Egypt’s Great Pyramid of Giza—one of the wonders of the ancient world, and a dazzling feat of architectural genius—contains a hidden void at least a hundred feet long, scientists announced on Tuesday.
The space’s dimensions resemble those of the pyramid’s Grand Gallery, the 153-foot-long, 26-foot-tall corridor that leads to the burial chamber of Khufu, the pharaoh for whom the pyramid was built.
However, it remains unclear what lies within the space, what purpose it served, or if it’s one or multiple spaces.
The void is the first large inner structure discovered within the 4,500-year-old pyramid since the 1800s—a find made possible by recent advances in high-energy particle physics. The results were published in the journal Nature.
“This is definitely the discovery of the century,” says archaeologist and Egyptologist Yukinori Kawae, a National Geographic Emerging Explorer. “There have been many hypotheses about the pyramid, but no one even imagined that such a big void is located above the Grand Gallery.”
The findings mark the latest in a millennia-long quest to understand the Great Pyramid of Giza, long an object of mystery and intrigue.
The pyramid was built some 4,500 years ago during the Fourth Dynasty of ancient Egypt’s Old Kingdom. At that time, Egypt was a powerful, highly centralized monarchy, wealthy from trade and Nile-nourished agriculture.
The Great Pyramid is arguably the ultimate expression of that power. The pharaoh Khufu, who reigned from 2509 to 2483 B.C., built for himself a pyramid whose base spreads across more than 13 acres and originally towered more than 146 feet tall. The monument consists of about 2.3 million limestone blocks, which had to be quarried, transported, cut to size, and moved into place. (Read more about the extraordinary Pyramids of Giza.)
“These sorts of pyramids are the major product, so to speak, of the kings who built them,” says Kate Spence, a University of Cambridge archaeologist who studies ancient Egypt. “An awful lot of Egyptian society is probably geared toward building pyramids at this particular time.”
Ever since, the Great Pyramid has drawn in the curious; today, tourists enter the pyramid through a tunnel created in the ninth century A.D. The National Geographic Society has helped conduct two explorations of the pyramid, including a 2002 exploration of the “air shafts” extending out one of the pyramid’s three chambers.