Scientists Are Investigating a Puzzling Underground ‘Anomaly’ Near the Giza Pyramids

Without breaking ground, archaeologists in Egypt have discovered an “anomaly” beneath a royal graveyard near Giza’s 4,500-year-old Great Pyramid.

The pyramid, which is Egypt’s largest, was built to honor the pharaoh Khufu. Its neighboring ancient necropolis contains many aboveground monuments, or mastabas, dedicated to the pharaoh’s family members and high-ranking officials.

“A mastaba is a type of tomb, which has a flat roof and rectangular structure on the ground surface, constructed out of limestone or mudbricks,” according to a study published this month in the journal Archaeological Prospection.

These surface-level tombs have vertical shafts connected to underground chambers. Many of the site’s mastabas were excavated in the 20th century, but one vacant area without any noteworthy aboveground features had been left unexamined.

Between 2021 and 2023, researchers from Higashi Nippon International University and Tohoku University in Japan and the National Research Institute of Astronomy and Geophysics in Egypt analyzed this empty area. Instead of a traditional excavation, they employed several non-intrusive imaging technologies—ground-penetrating radar and electrical resistivity tomography—to study the site. The resulting scans revealed something strange.

“We believe we found an anomaly: a combination of a shallow structure connected to a deeper structure,” write the researchers in the study. The shallow structure is clearly L-shaped, and the scans indicate it was filled in with sand after construction. At one point, “it may have been an entrance to the deeper structure.”

The L-shaped structure is about 33 feet long, and it’s buried 6.5 feet deep, reports Live Science’s Owen Jarus. Below it, the scans show another structure—a “highly resistive anomaly.” While the researchers aren’t sure of the deeper structure’s contents, they say it could be empty or filled with materials such as sand and gravel.

While many questions remain, the scans “point to the possibility of the presence of archaeological remains,” write the researchers. “It is important that they must be promptly excavated to establish their purpose.”

Excavations are currently underway, reports Live Science. Lead author Motoyuki Sato, an expert in electromagnetic sensing technologies at Tohoku University, is optimistic. “The L-shape cannot be created in natural geological structures,” he says, per the Art Newspaper’s Garry Shaw.

Of course, these anomalies aren’t the cemetery’s only subterranean structures. Previous excavations have revealed underground chambers that are part of the site’s many mastabas, which are marked by tombs on the surface. The graveyard’s vacant area, unmarked by such a tomb, had previously “avoided exploration,” as Peter Der Manuelian, an Egyptologist at Harvard University who wasn’t involved in the research, tells Live Science. He says that Giza contains some other L-shaped offering chapels, but they’re usually above ground.

“I’m not sure just what this anomaly represents yet,” he adds. “But it is certainly worthy of further exploration.”

Sonja Anderson | READ MORE

Sonja Anderson is a writer and reporter based in New York City.