The pyramids of Giza are among the most famous buildings of antiquity, but they still have surprises to offer. Now archaeologists have discovered new cavities while examining the Menkaure pyramid – the smallest of the three pyramids. Behind the granite cladding of the east facade, radar, ultrasound and conductivity measurements showed two anomalies indicating air-filled cavities. From the location, the team concludes that it could be a former second entrance to the pyramid.
The Pyramids of Giza are the last remaining wonder of the ancient world and are world famous. The three monumental buildings were built more than 4,500 years ago for the Egyptian pharaohs Cheops, Chephren and Menkaure (Mykerinos). The enormous tombs were intended to serve as a transitional aid for the royal dead into the afterlife. Inside there is a branched network of corridors, chambers and dead ends that were intended to protect the graves and treasure chambers from grave robbers. But what is hidden inside the three famous pyramids is still only partially known today. However, using new technology, archaeologists have recently discovered several previously unrecognized structures, including a large passage and chamber in the Great Pyramid of Cheops and a passage in the Pyramid of Chephren.
Polished surface on the east facade
Now there is also news about the third pyramid of Giza, the pyramid of Pharaoh Menkaure, also called Menkaure. He was probably a son of the Pharaoh Chephren and ruled Egypt from 2530 to 2510 BC. At 65 meters high, his tomb is the smallest of the three Giza pyramids. But it has a special feature: the step pyramid made of limestone blocks is clad in granite slabs in the lower part – the other pyramids had a limestone facade. “Originally, these plates formed 16 to 18 horizontal rows, but today only seven of them remain,” report Khalid Helal from Cairo University and his colleagues.
The granite blocks of the facade cladding are usually only roughly hewn and uneven. But at the currently only entrance to the Menkaure pyramid on the north side and at an otherwise inconspicuous place on the eastern facade, these blocks are noticeably smoothed: “These surfaces stand out due to their polished, accurately fitted blocks,” report the archaeologists. On the east facade, this area is around four meters high and six meters wide and is located in the lower part of the pyramid. Researchers have long suspected that there might also be an as yet undiscovered entrance hidden on the eastern side of the Menkaure pyramid.
Two anomalies behind the granite cladding
In order to track down this possible pyramid entrance, Helal and his team examined the eastern facade of the Menkaure pyramid using three different technologies. “Our goal was to detect possible cavities behind the conspicuous areas,” they report. Georadar, ultrasound and electrical resistance tomography (EST) were used. “Resistivity tomography measures the electrical resistance and conductivity of materials and can thus detect boundaries between stone and air,” explain the archaeologists. They used this technique to examine a large part of the eastern facade in order to initially identify potentially conspicuous areas. These were then analyzed in more detail using georadar and ultrasound, both of which penetrate slightly deeper and provide more detailed information about the structure.
The result: “Our images revealed two anomalies directly behind the polished granite blocks,” report Helal and his colleagues. “They likely represent air-filled voids in the limestone structure that begin directly beneath the granite cladding of the east façade.” The larger cavity is around one meter high and 1.50 meters wide, the second is slightly smaller at 90 by 70 centimeters. “It was difficult to determine how far these anomalies extend into the interior of the pyramid,” the archaeologists write. “The penetration depth of our methods was not sufficient.” In their opinion, however, it is quite possible that these cavities belong to a passage that leads into the interior of the pyramid.
Possible second entrance
The newly discovered cavities could therefore be the remains of another entrance to the Menkaure pyramid. “Our discoveries take us a big step forward in confirming this,” says co-author Christian Große from the Technical University of Munich. “After the significant discovery of an unknown chamber in the Great Pyramid in 2023, an important discovery has once again been made in Giza.” According to archaeologists, it might be worth following up on this new lead and examining the eastern facade of the Menkaure pyramid and its interior in more detail. “The interpretation of the anomalies discovered should also be further discussed among Egyptologists,” said Helal and his team.
Source: Technical University of Munich; Specialist article: NDT&E International, doi: 10.1016/j.ndteint.2025.103331