The pyramids and the Great Sphinx of Giza are some of the most well-known monuments in the world. But around them, beneath the sands of Egypt, there are still plenty of undiscovered secrets. Recent advancements in geophysical exploration techniques have enabled archaeologists to peer deeper into the past without disturbing the ground.

In a new study, researchers employed two geophysical methods called Ground-Penetrating Radar (GPR) and Electrical Resistivity Tomography (ERT) to explore the Western Cemetery at Giza, showing the presence of large, unexplored structures beneath the surface.

Not everyone can afford a pyramid

Archaeology traditionally involves the painstaking process of excavation. But you don’t always need to dig to get an idea of what’s underground. The surveys at the Western Cemetery employ GPR and ERT— methods that allow archaeologists to peek underground without digging. GPR works by emitting radio waves into the ground and detecting the signals that bounce back, revealing buried structures. ERT, on the other hand, measures the electrical resistance of the soil to identify different materials below the surface. These techniques are not innovative, but they are useful in places like the Western Cemetery, where every unturned stone could be a link to the distant past.

The Western Cemetery, adjacent to the Great Pyramid of Giza, is a significant necropolis for high-ranking officials and members of the royal family from Egypt’s Old Kingdom. They’re still people that would have been rich and influential, just not rich enough to afford a pyramid.

The cemetery spans approximately 560 meters (1837 ft) east to west and 370 meters (1214 ft) north to south, densely packed with mastabas of various sizes. However, a conspicuous area in the middle of the cemetery, measuring about 80 by 110 meters (262 by 328 ft), appears devoid of any above-ground structures. This area, bounded by known mastaba fields and an enclosure wall, has remained largely unexplored until now.

Ancient discoveries in the desert

The prospection surveys were carried out between 2021 and 2023. Initially, researchers found an area devoid of visible structures. Then, at one point, using GPR surveys, they came across a distinct L-shaped structure about half a meter below ground. This feature was roughly 10 x 10 meters (1076 ft²) in size, appearing to be a passageway that led to a deeper structure.

The researchers returned with ERT, which can penetrate to greater depths, and they found an area of resistive anomaly. In other words, something is down there that’s more resistive to current — most likely, a large burial chamber or a built structure. Quite possibly, the L-shaped structure was used to support the construction of the larger chamber or as a passageway to it. All of this hints at a complex, multi-layered structure.

This is the most striking discovery, but it’s not the only one. Researchers found plenty of areas of interest that likely hold valuable clues regarding life in Ancient Egypt. All these findings emphasize that there’s a lot of undiscovered archaeology around the Great Pyramids. So, non-invasive methods are important, enabling researchers to explore and map ancient sites cheaply and quickly, without disturbing the ground.

For now, it’s unclear if archaeologists will actually dig this site — but if they do, they know exactly where to start. Modern archaeology isn’t always about finding big monuments, it’s often about figuring out what ancient life would have been like.

Journal Reference: Motoyuki Sato et al, GPR and ERT Exploration in the Western Cemetery in Giza, Egypt, Archaeological Prospection (2024). DOI: 10.1002/arp.1940