Is there a hidden Hall of Records under the Great Sphinx?

What archaeology found: who built the Great Sphinx

The direct answer is no. No excavation, radar survey or seismic study has produced a verified hidden chamber beneath the Great Sphinx. What the evidence does show is how the monument was made: workers cut a deep U-shaped ditch into the Giza plateau's limestone bedrock and left a single massive block standing inside it, then carved that block into the lion-bodied, human-headed statue. Egypt's Ministry of Tourism and Antiquities dates the carving to the 4th Dynasty, "c. 2613–2494 BC," and says the evidence points to it being carved during the reign of Khafre, "c. 2558–2532 BC."

How the Great Sphinx was built

Mark Lehner, field director of the 1979-1983 ARCE Sphinx Project and later founder of Ancient Egypt Research Associates (AERA), writes that "Khafre created most of the Sphinx," though "Khufu might have started it." AERA's geologist Tom Aigner matched three geological layers inside core blocks of the adjacent Sphinx Temple to the same three layers visible in the Sphinx's body, evidence that the temple's stone was quarried directly out of the ditch that shaped the statue. Harvard's Digital Giza Project, more cautiously, calls Khafre "probably" the builder.

Mapping the monument and its repairs

Before 1979, no scale drawings of the Sphinx existed. Lehner spent five years producing the first master plan, elevations, sections and profiles, sponsored by the American Research Center in Egypt. The survey also recorded the statue's solar alignment and a long history of masonry repair and restoration, running from antiquity through the Roman period. Harvard's Digital Giza Project separately notes a restoration campaign under Thutmose IV, about a thousand years after Khafre, and credits the Egyptologist Selim Hassan with clearing the sand that had buried the body and its amphitheater.

The mainstream explanation

Mainstream Egyptology treats the Sphinx as a single Old Kingdom project, not an older monument re-carved later. The quarry-to-temple stone match ties the statue directly to Khafre's building program, and it is why the Ministry of Tourism and Antiquities, AERA and Harvard's Giza Project all date the carving to his reign, around 2558 to 2532 BC. National Geographic frames Khafre as the likely builder while noting flatly that "no one can say for sure," a caution aimed less at rival pharaohs than at fringe ideas such as, in the magazine's words, theories that "point fingers at space aliens."

Popular alternative claims: Edgar Cayce's Hall of Records

The best-known alternative claim comes from Edgar Cayce, an American who gave trance "readings" from the 1900s to the 1940s and became an early figure in the New Age movement. Cayce said refugees from a lost civilization called Atlantis buried a "Hall of Records" of their knowledge in a chamber reachable through a passage connected to the Sphinx's right paw. National Geographic reports that despite the legend, "nothing has been found, according to bemused archaeologists."

Cayce's own foundation, the Association for Research and Enlightenment, still publishes the reading on the subject, which says only that the chamber would open "as time draws nigh when changes are to come about" and "when the changes must be active in this sphere of man's experience." That wording gives no calendar date. A specific 1996-to-1998 discovery date is often repeated online, but it does not appear in the foundation's own published material on the reading, and this record could not confirm it in a source reliable enough to cite.

Popular alternative claims: Robert Schoch's older Sphinx

The geologist Robert Schoch argues the "core-body" of the Sphinx is far older than the Old Kingdom, dating it, in his words, to "at least 5000 BCE" and, in his more recent view, to "the end of the last ice age, circa 10,000 BCE." His reasoning rests on erosion patterns on the statue and its enclosure walls that he attributes to heavy rainfall and water runoff, in a climate wetter than today's, rather than the wind and blowing sand that weathered other securely dated Old Kingdom structures nearby.

In the early 1990s, Schoch's team ran a seismic survey, striking a steel plate with a sledgehammer and reading the resulting sound waves with geophones. He reports the data showed unusually deep subsurface weathering under the Sphinx enclosure and what he describes as "evidence of a cavity or chamber under the left paw of the Sphinx." Mainstream Egyptologists, working from the quarry and stone-matching evidence described above, have not adopted Schoch's older date or confirmed his claimed cavity through excavation.

Popular alternative claims: the 2025 radar claims

In March 2025, the physicist Corrado Malanga of the University of Pisa, working with Filippo Biondi and Armando Mei, announced at an Italian press conference that satellite radar imaging showed "massive vertical shafts, spiral staircases" and channels resembling a water system more than 2,000 feet under the Pyramid of Khafre, next to the Sphinx. Some coverage linked the claim to Cayce's Hall of Records. The team said, according to Euronews, that further work would reveal "what can only be described as a true underground city."

The claim drew immediate pushback. Lawrence Conyers, a radar specialist at the University of Denver, called it a "huge exaggeration" and said satellite radar cannot penetrate that far underground. Zahi Hawass, Egypt's former antiquities minister, told the news outlet The National the team was "completely wrong" and that the discovery "lacks any scientific basis." The findings were never published in a peer-reviewed journal. Separately, in 2026 the journal Remote Sensing retracted a 2022 paper by Biondi and Malanga on the nearby Great Pyramid of Khufu, citing "serious methodological flaws and statistical errors," Newsweek reported.

What is still unsolved

AERA's own mapping traced repair and restoration work at the Sphinx across many centuries, from the Old Kingdom through the Roman period, so the statue's interior is not a single untouched block; it carries small voids and patched sections from that long history. No public inventory ties each of those features to a location or explains them all. That gap, more than any single legend, is what keeps claims about what else might be hidden in circulation, even though none of the specific claims above has held up.

Questions people ask

Verdict

The Great Sphinx mystery, stripped of the Atlantis and underground-city stories, comes down to solid but incomplete archaeology: a statue carved from the Giza bedrock, most likely on Khafre's orders around 2558 to 2532 BC, mapped in detail by Lehner's team but never fully inventoried below the surface. Real or Legend stamps this record disputed. The Old Kingdom, Khafre-built explanation has real physical evidence behind it; the Hall of Records, Schoch's much older Sphinx and the 2025 radar claims do not, and Egyptologists have rejected the most recent of them outright.