The Pyramid That Refuses to Give Up Its Secrets

How ScanPyramids’ cosmic-ray discovery opened the door for Filippo Biondi’s radar-tomography work—and the strange new maps that followed.

At Giza, the Great Pyramid looks like certainty carved in stone: a human-made mountain with four sharp edges fixed against the horizon. But in the modern age, certainty is exactly what the pyramid seems to resist. Not because it is collapsing into mystery, but because every time researchers point a new kind of instrument at it—particles, heat, sound, radar—the stone responds with another unexpected shape.

Over the past decade, that exchange has become far more technical, and far more cinematic. It begins with cosmic rays from deep space. Then, almost improbably, it leads to satellites and to the idea that the pyramid might be “seen” not by sending a signal through it, but by watching how it moves.

When cosmic rays found a room

For years, the Great Pyramid’s inner layout seemed like a closed book: the Descending Passage, the Grand Gallery, the King’s Chamber, the Queen’s Chamber—famous, surveyed, debated, and seemingly complete.

Then ScanPyramids arrived with a method that sounds like science fiction but works like engineering: muography, also known as cosmic-ray muon radiography. Muons are highly penetrating particles that constantly fall through Earth’s atmosphere. Place detectors in the right spots, wait long enough, and the pyramid effectively becomes a filter. Denser stone blocks more muons. Empty spaces let more pass through. What comes out is not a photograph, but a density map—an X-ray-style logic applied to a monument the size of a small hill.

In 2017, the ScanPyramids team announced the finding that made the world pay attention: a “large void” above the Grand Gallery, with a cross-section similar to the gallery itself and a minimum length of roughly 30 meters.

That discovery mattered not only because of its size, but because it was the first major internal structure reported inside the Great Pyramid since the 19th century. It showed that the most famous building on Earth could still contain unknown space.

Then came another discovery, smaller but easier to picture: a corridor-like structure behind the so-called Chevron zone on the pyramid’s north face. In 2023, ScanPyramids published a detailed characterization of it, describing a corridor at least five meters long. In 2025, researchers using Electrical Resistivity Tomography, or ERT, reported evidence for that same North Face Corridor through another non-destructive method.

By then, the pyramid had started to resemble a reluctant patient in a highly advanced scanning suite. Muons, resistivity, radar, ultrasound—one method after another, compared and layered together. The logic was simple: you do not take one image and declare the mystery solved. You come back with another instrument and see whether the stone gives the same answer again.

Filippo Biondi and a different kind of visibility

If ScanPyramids offered a new way to detect hidden voids, Filippo Biondi wanted something broader: a way to reconstruct the pyramid more like a 3D model than a single “something is here” marker.

Biondi, an engineer at the University of Strathclyde, and Corrado Malanga, from the University of Pisa, presented the idea in a 2022 paper with a striking title: “Synthetic Aperture Radar Doppler Tomography Reveals Details of Undiscovered High-Resolution Internal Structure of the Great Pyramid of Giza.”

The key point is this: ordinary radar does not easily see through thick stone. The authors acknowledge that directly. But instead of trying to force radar through the monument like an electromagnetic drill, they focus on something else: tiny movements.

The Great Pyramid is not completely still. It is constantly being stirred by the background noise of the planet—small seismic waves, wind, distant vibrations. Biondi and Malanga propose that a long series of satellite SAR images can capture these subtle motion signatures. From those signatures, they argue, it is possible to build a kind of tomographic reconstruction: an interior map inferred from how different parts of the structure respond.

Their paper describes the processing of SAR image series from Italy’s second-generation COSMO-SkyMed satellite system and reports what they call “high-resolution full 3D tomographic imaging” of the pyramid’s interior and subsurface.

For a remote-sensing paper, it is an unusually poetic claim. In the abstract, the authors even say the pyramid “becomes transparent” when viewed through this micro-movement domain.

The new maps: known chambers, then unfamiliar labels

One reason Biondi’s work drew attention is that it does not begin with fantasy. It begins with orientation. The reconstruction lines up with known architecture: chambers and corridors already documented by explorers, surveyors, and modern research missions.

Then the paper moves into its bigger claim: additional structures and connections that the authors label and list. In the article’s table of structures, they include entries such as a “little void,” a “front corridor,” and a “big void,” along with multiple corridors and more complex forms.

For anyone familiar with ScanPyramids, those terms feel familiar. “Big void” is now a well-known phrase because of the 2017 muon discovery. The corridor behind the Chevron zone is also a ScanPyramids result, and by 2025 it had been investigated through ERT in a separate Scientific Reports study.

So Biondi’s reconstructions sit inside a larger scientific story. Some voids are already known from other methods. That creates an intriguing rhythm: first, the pyramid offers a few confirmed surprises through ScanPyramids. Then a new method arrives—Biondi’s SAR Doppler tomography—claiming to show not just isolated points, but a wider network of shapes.

It is not hard to understand the appeal. The method promises a kind of remote sensing that feels less like “finding emptiness” and more like recovering a hidden blueprint.

How the story jumped from journals into popular culture

In March 2025, the topic moved from technical discussion into the noisy center of internet fascination. Claims began circulating about a vast underground network beneath the Giza pyramids, supposedly revealed by “radar images.” Euronews described the moment as a public dispute, with researchers promoting an extraordinary underground interpretation and Egyptologists pushing back strongly.

What made the story explosive was the scale. People were no longer just talking about a corridor or a void. They were talking about a subterranean system—vertical shafts, sweeping features, and something more like hidden infrastructure than a sealed tomb.

Biondi’s name became part of that conversation, especially because his published work is based on satellite SAR and makes ambitious claims about imaging internal and subsurface structures.

Official responses followed quickly. On March 26, 2025, Zahi Hawass issued a public statement calling the viral claims “false” and challenging the radar-based narrative around the “Khafre Project.” Newsweek also covered the controversy, summarizing Hawass’s dismissal and the wider debate around the underground-city claim.

And yet, this is what keeps the story alive: controversy does not always end curiosity. Sometimes it sharpens it. Once the pyramid is seen as a place where new scanning technologies can still reveal surprises, every new dataset begins to feel like the next possible chapter.

Why Biondi’s method feels so different

ScanPyramids is, in one sense, simple and elegant: cosmic particles go in, a density map comes out. The results appear as bounded mysteries—“there is a void here”—that can be refined with more measurements.

Biondi’s approach feels more like listening than looking. It suggests that if you can measure the pyramid’s tiny involuntary movements over time, you can work backward from those signals and infer structure. The idea is compelling because it changes how we imagine the monument. It is not just static stone waiting to be penetrated. It becomes a responsive object whose internal layout affects the way it vibrates.

The method also has a striking practical implication. Satellites do not need permission to sit inside a corridor for months. They do not need to install instruments in a chamber. They observe from above, again and again, building a time-series memory of the structure’s behavior.

That is the core of the Biondi story: the pyramid as a signal processor, a giant stone instrument quietly played by the background noise of Earth.

The pyramid as a testing ground for modern sensing

Seen from a wider angle, what is happening at Giza is bigger than any single void or corridor. The pyramids have become a testing ground for non-destructive investigation: a place where particle physics, geophysics, and satellite remote sensing all try to prove themselves on the world’s most scrutinized architecture.

ScanPyramids gave the field a modern discovery story grounded in peer-reviewed measurement: the Big Void above the Grand Gallery. It also helped establish the idea that smaller, targeted anomalies—such as the North Face Corridor—can be detected, described, and then checked with other methods like ERT.

Biondi’s work points toward a more expansive possibility: that satellites could reconstruct interior and subsurface details at high resolution through micro-motion analysis, producing structured inventories of rooms, corridors, and connections, including features labeled “little void” and “big void.”

The next chapter, if it is going to satisfy both curiosity and scientific discipline, will need what Giza increasingly demands: converging evidence. Not one image, but many. Not one sensor, but a chorus of them. And perhaps eventually, a minimally invasive look inside one of these mapped spaces—a camera probe small enough to turn a persuasive model into a confirmed room.

Until then, the Great Pyramid continues doing what it has always done best: standing perfectly still while the most advanced tools of each era circle around it, trying to discover what it has been hiding in plain sight.