Scientists Detect Two Hidden Voids Behind Menkaure Pyramid — Could This Be a Secret Entrance?

Hidden cavities discovered behind Menkaure’s eastern granite could mark a concealed entrance

Rising beside the Great Pyramid of Khufu and the imposing monument of Khafre, the Pyramid of Menkaure has stood for more than 4,000 years. Weathered by desert winds, damaged by looters and a 12th-century order to dismantle the pyramids, Menkaure still guards mysteries beneath its stone facade.

Unusual eastern face: One distinctive feature is the pyramid’s eastern facade, once faced with polished granite slabs — material typically used at entrances. That detail prompted researchers to investigate whether something lay behind those slabs.

Non‑invasive scanning reveals two voids

A team from Cairo University and the Technical University of Munich, working with the ScanPyramids project (the same group that previously identified a hidden corridor in the Great Pyramid), used three non‑destructive techniques: Electrical Resistivity Tomography (ERT), Ground Penetrating Radar (GPR) and Ultrasonic Testing (UST). These methods probe internal structure without excavation.

Combined results identified two air‑filled anomalies behind the eastern granite slabs — anomalies first proposed by researcher Stijn van den Hoven in 2019. Both cavities are substantially larger than the minor gaps visible where erosion exposed the pyramid’s interior, and the larger void appears large enough to accommodate a human-sized space. That makes the possibility of a deliberately concealed or otherwise significant opening plausible.

What the methods show — and their limits

ERT maps subsurface resistivity contrasts and can flag cavities by how they oppose electrical flow. GPR sends electromagnetic pulses into stone and records echoes to estimate depth and geometry. UST uses sound waves to measure wall thickness and detect boundaries between stone and air. Together, these methods located the starting depths and approximate dimensions of the two anomalies.

However, the team cautions that the penetration depth of these techniques is limited in this setting, so the full extent and orientation of the voids remain uncertain. Further non‑invasive surveys with complementary methods, or carefully planned archaeological exploration approved by Egyptian authorities, would be required to map how far the cavities extend and determine whether they represent a deliberate entrance, a construction feature, or later modification.

Why Menkaure’s pyramid is smaller — and why it still matters

Scholars continue to debate why Menkaure’s monument is markedly smaller than those of Khufu and Khafre. Ancient accounts suggest Menkaure may have expected an early death after a prophetic dream, possibly prompting a shorter building program. Whatever the reason, these newly detected voids underline that even well-studied monuments on the Giza Plateau can still yield surprises.

The results were published in the journal NDT&E International. Researchers emphasize the need for further study to confirm the depth, extent and purpose of the detected cavities.