Japanese experts believe that they have found previously undetected cavities inside the 4,600-year-old Pyramid of Cheops, a possible discovery that would further challenge the long-held belief that the Great Pyramid is filled mostly with stones.
"We believe the pyramid has more space than people think," team leader Sakuji Yoshimura said. "If we can prove it, that means the pyramid is not made up of millions of stones but only around 200,000 blocks."
In 1986, a team of French researchers also found what they believed were three cavities in the Pyramid of Cheops. But after drilling holes through an interior wall, the scientists suspended their explorations because the effort turned up only sand--instead of Pharaonic treasures.
The Great Pyramid is one of three big pyramids at Giza near Cairo, believed to be tombs of three Pharaohs of ancient Egypt.
Yoshimura said he was puzzled that the rooms in the Cheops Pyramid--called the King's Chamber, the Queen's Chamber, the Grand Gallery--and connecting passages lay to the east of its center, with no cavities evident to the west.
If he can prove his theory that the pyramid contains more space than stone, the pyramid would become a "soft structure," in architectural terms.
It also would date this method of pyramid-building to the Old Kingdom of Egyptian archeology, earlier than previously thought, he said.
"We have made a new find which is very important, very mysterious," Yoshimura said.
Using electromagnetic scanners to probe sound waves behind interior surfaces, his team found a 90-foot passage parallel to the so-called Queen's Chamber, apparently veering off to the west side of the pyramid, previously thought to contain only stones.
"This is a key to a possible connection between the east and west sides of the pyramid," Yoshimura said.
He said two other spaces were found in the King's Chamber, one under the Pharaoh's sarcophagus, the other between the chamber and the Grand Gallery, a steep limestone passage 153 feet long and 30 feet high.
After research in February on Cheops and the nearby Sphinx, a monument with a human face and a lion's body, Yoshimura's team, from Tokyo's Waseda University, returned on a nine-day expedition this month to confirm previous findings.
Yoshimura surmised that the pyramid was built as a symbolic festival hall for souls on their return from the afterworld--rather than as a tomb.
"We should find passages, corridors, but not Cheops' tomb. Possibly a burial chamber (containing funerary objects) but not a tomb," he said.
"About 99% of the ancient Egyptians buried their dead underground."
The tomb of Cheops, whose mummy was never found and was thought stolen by grave-robbers, was probably west of his pyramid, in a different-shaped structure, he said.
Yoshimura stressed that his theories could take a long time to confirm.
"But we will not hurry with our investigations because 5,000 years have passed since the pyramid was built. We have waited that long; we have much time," he said.