There is an underground megastructure beneath the Giza Plateau
Beneath the windswept sands of the Giza Plateau, Italian researchers have proposed that humanity's most iconic monument may have a twin — a second Sphinx, long buried and long forgotten, waiting beneath a mound of solidified earth. Drawing on satellite radar, ancient geometry, and a carved stone slab erected by a pharaoh who dreamed of sphinxes, the team from the University of Pisa has offered not a certainty but a compelling convergence of evidence, one that invites the oldest of human questions: what else have we failed to see, hiding in plain sight beneath the world we think we know?
- A team of Italian scientists has announced with 80% confidence that a second Sphinx lies buried beneath a 180-foot sand mound on the Giza Plateau, mirroring the position of the original.
- The claim reignites a long-dismissed theory rooted in the Dream Stele — a 3,400-year-old carved slab depicting two sphinx figures — which Egyptologist Bassam El Shammaa spent decades championing against institutional skepticism.
- Satellite radar capable of detecting minute ground vibrations revealed dense vertical structures beneath the mound, patterns the researchers interpret as underground shafts and passageways consistent with those already confirmed beneath the existing Sphinx.
- If the underground formations date to 38,000 years ago as the team suggests, the discovery would shatter conventional timelines of ancient Egyptian civilization and reframe the entire Giza complex.
- The researchers are urging on-site geological study before any conclusions are drawn, acknowledging that the mound's true composition — solidified sand or natural bedrock — remains the critical unanswered question.
Beneath the Giza Plateau, Italian researchers believe, lies a twin to Egypt's most famous monument — a second Sphinx, concealed beneath a mound of solidified sand roughly 180 feet high. The claim rests on a rare convergence: ancient imagery, geometric precision, and satellite radar technology capable of reading the earth's hidden architecture.
The story has older roots. The Dream Stele, carved around 1401 BCE by Pharaoh Thutmose IV and placed between the paws of the Great Sphinx, depicts two sphinx figures. For decades, Egyptologist Bassam El Shammaa argued this was not decoration but documentation — evidence of a second guardian that once existed, or still does, buried somewhere on the plateau. The theory was dismissed by prominent figures in Egyptology, but it never fully faded.
In 2025, a team led by Corrado Malanga of the University of Pisa and Filippo Biondi announced the detection of vast underground structures beneath Giza — formations they estimated to be as old as 38,000 years, far predating the 4,500-year-old pyramids above them. Then, in March 2026, Biondi went further. Using satellite radar that detects minute ground vibrations, his team drew geometric lines from the pyramids to the existing Sphinx, extended and mirrored them, and arrived at a precise location on the plateau. Beneath the sand mound at that spot, the radar revealed dense vertical patterns — structures the team interpreted as shafts and passageways strikingly similar to those beneath the original Sphinx.
"Down underneath the Giza Plateau, there is something very huge that we are measuring," Biondi said. "There is an underground megastructure." He expressed 80% confidence in the geometric correlation, while remaining careful not to overreach. The next step, he stressed, is geological fieldwork — boots on the ground, hands in the earth, confirming whether the mound is truly solidified sand shaped by human intention or simply natural formation.
What the earth holds beneath that 108-foot rise remains, for now, unanswered. But the convergence of the Dream Stele's imagery, the geometric symmetry, and the radar signatures has given new life to a theory once thought buried as deeply as the structure it describes.
Beneath the Giza Plateau, Italian researchers say, lies a mirror image of Egypt's most famous monument—a second Sphinx, twin to the colossal guardian that has watched over the desert for millennia. The claim rests on geometry, ancient stone, and satellite radar that can read the earth's whispers.
The story begins with a stele, a carved stone slab erected around 1401 BCE by Pharaoh Thutmose IV. The Dream Stele sits between the paws of the Great Sphinx itself, and on its surface are depicted two sphinx figures. For decades, Egyptologist Bassam El Shammaa proposed that this carving was not mere decoration but a literal record—evidence that a second sphinx once existed, or still does, hidden somewhere beneath the plateau. The theory was dismissed, notably by former antiquities minister Zahi Hawass. But it never quite disappeared.
In 2025, a team led by Corrado Malanga of the University of Pisa and Filippo Biondi, formerly of the University of Strathclyde, announced they had found vast underground structures beneath the Giza Plateau. The pyramids themselves are roughly 4,500 years old, they said. But the structures below—the ones they were detecting—appeared to be far older, perhaps 38,000 years. This discovery opened a door. If there were underground complexes of that age, what else might be buried there?
On March 26, Biondi appeared on the Matt Beall Limitless podcast with a new announcement. Using advanced satellite radar technology that detects minute vibrations in the ground, his team had drawn geometric lines from the pyramids to the existing Sphinx. These lines, when extended and mirrored, pointed to a precise location on the plateau. At that spot sits a mound of sand roughly 180 feet high—not natural bedrock, the researchers believe, but solidified sand, deliberately piled or shaped. Beneath it, the radar scans suggested, lay vertical shafts and passageways strikingly similar to those found beneath the original Sphinx. Biondi expressed confidence in the finding, claiming 80 percent certainty in the geometric correlation. "We are finding precise geometrical correlation, 100 percent of correlation, in this symmetry," he said, though the 80 percent figure suggested some caution remained.
The radar data itself showed dense vertical lines in the scans—patterns the team interpreted as solid walls of underground shafts rather than empty voids. To Biondi, this pointed to something vast. "Down underneath the Giza Plateau, there is something very huge that we are measuring," he said. "There is an underground megastructure." The mound above this suspected second Sphinx rises about 108 feet above the surrounding terrain. The original Sphinx sits slightly below the surface level of the plateau. A second one, Biondi reasoned, could easily be concealed beneath a higher mound.
What makes the claim intriguing is not just the radar data but the convergence of evidence. The Dream Stele's depiction of two sphinxes, the geometric precision of the proposed location, the underground structures already confirmed beneath the plateau, and the radar signatures all point in the same direction. In ancient Egypt, sphinxes were guardians—benevolent protectors of temples and tombs. They typically had human heads and lion bodies, though variations existed: ram-headed criosphinxes linked to the god Amun, falcon-headed hieracosphinxes. The Great Sphinx itself, roughly 73 meters long and 20 meters high, is the world's largest monolithic statue, carved around 2500 BCE during the reign of Pharaoh Khafre, whose face it is thought to bear.
But Biondi is careful not to overstate. He emphasizes that what has been found so far is suggestive, not conclusive. The next step requires geologists on site, studying the mound directly, examining its composition, confirming that it is indeed solidified sand rather than natural formation. "For the second Sphinx, it is important to go in situ with geologists and carefully study the mound," he said. "We are very confident that it is not bedrock. The sand has been solidified." The claim awaits ground truth. What lies beneath that 108-foot mound remains, for now, a question the earth has not yet answered.
Notable Quotes
We are finding precise geometrical correlation, 100 percent of correlation, in this symmetry. We are very confident to announce this—we have a confidence about 80 percent.— Filippo Biondi, researcher
For the second Sphinx, it is important to go in situ with geologists and carefully study the mound. We are very confident that it is not bedrock. The sand has been solidified.— Filippo Biondi
The Hearth Conversation Another angle on the story
Why should we believe this now, when the theory has been around for decades and dismissed by serious Egyptologists?
Because they have new tools. Satellite radar that can detect ground vibrations is not the same as speculation. The geometry they're describing—lines from the pyramids to the existing Sphinx, mirrored to a precise point—that's testable. It's not proof, but it's a specific claim that can be verified or falsified.
The 80 percent confidence figure—that seems oddly precise for something so speculative.
It does. I think what they mean is they're 80 percent confident in the geometric correlation itself, the mathematical relationship. But that's different from being 80 percent confident a sphinx is actually there. The radar shows something beneath that mound. What it is, they don't yet know.
If this second sphinx exists, how old would it be? The source mentions 38,000 years for the underground structures.
That's the unsettling part. If the underground complex is really that old, it predates everything we think we know about Egyptian civilization by tens of thousands of years. It would rewrite the timeline entirely. But that claim itself is controversial. Most archaeologists are skeptical of those dates.
So what's the actual next step?
Excavation. Careful, methodical digging and geological study of that mound. They need to confirm it's solidified sand, not bedrock. They need to find those shafts and passageways the radar suggests. Until someone digs, it remains a theory supported by geometry and radar signatures—compelling, but not proven.
Why would a second sphinx be hidden, if the first one is so visible?
That's the mystery. Maybe it was buried intentionally, for reasons we don't understand. Maybe it was damaged and covered over. Or maybe the Dream Stele is just depicting the same sphinx twice, and we're reading too much into it. That's why the ground truth matters so much.