A rectangular shaft about five feet wide and six feet deep is cut into the top of the Great Sphinx’s head, directly into the skull of a statue long assumed to be solid rock. Discovered by the team of French engineer Émile Baraize during excavation work in the 1920s, the opening was later sealed with cement and an iron cover. It is not the only one. Additional openings exist at the back, beneath the chest, and near the tail, each leading into the body or downward into the bedrock. All have been found, opened, and subsequently closed again.
The Sphinx itself was carved from a single mass of limestone on the Giza Plateau around 2500 BCE, most likely during the reign of Pharaoh Khafre. It stretches roughly 240 feet in length and stands about 66 feet high. No inscription from its own time names the people who carved it or explains its purpose, making it one of the quietest monuments in Egypt. Even the name is borrowed: “Sphinx” is a Greek term attached to the statue some two thousand years after its creation, while the Arabic name “Abu al-Hawl” translates to “Father of Terror.”
The proportions have long struck observers as uneven. The face, about 13 feet wide, sits on a body that extends far behind it, as if the lion had been stretched. For most of its history, the body was hidden beneath sand, with only the head visible. The statue was repeatedly excavated and reburied over the centuries and was not fully cleared in modern times until the 1920s and 1930s.
The earliest recorded story about the Sphinx comes from the Dream Stela, a pink granite tablet placed between its paws around 1400 BCE by Pharaoh Thutmose IV. The inscription describes how Thutmose, then a young prince, fell asleep in the shadow of the buried head and dreamed that the Sphinx spoke to him, promising the throne if he cleared away the sand. He did so and became king. For a long time, scholars read this as royal propaganda rather than literal history, but stories of access to the interior persisted. In the 16th century, German traveler Johann Helffrich reported an entrance leading into the head, with a priest speaking from inside while people below believed the statue itself was talking. In the first century, the Roman writer Pliny the Elder recorded a local belief that a king named Horemakhet was buried within the structure.
When the sand was finally removed, the stone produced openings in locations roughly matching those accounts. In 1798, during Napoleon’s campaign in Egypt, the French artist Vivant Denon depicted workers being pulled from a hole on top of the head. In 1925, Baraize began an eleven-year project for the Egyptian antiquities service to clear the monument. His team recorded a nearly square shaft, about five feet wide and six feet deep, cut vertically into the top of the skull. Photographs from that period show a man standing inside it, the opening reaching roughly chest height. Baraize lined the shaft with cement and covered it with iron. The cover remains there today, visible only from above.
A common explanation is that the shaft served as a socket for a crown or headdress added during the New Kingdom, when the Sphinx was worshiped as a living deity. No such crown has ever been found, however, and no fixture or fragment has been clearly attributed to one. Some researchers have suggested that later visitors deepened the shaft while searching for something below the surface. The head was carved from a harder, denser layer of limestone than the body, making it the most durable part of the monument and the most plausible location for an internal chamber, though excavations found only solid rock at the bottom.
The second opening is on the back, just behind the head. In 1837, British army officer Howard Vyse, known for using gunpowder to force his way into sealed chambers in the Great Pyramid, drilled into the Sphinx’s body. At a depth of 27 feet, his rods struck something, and he stopped after considering the risk of damaging the statue. The cavity remained open for decades. When Egyptian archaeologist Zahi Hawass cleaned it in 1978, it contained a fragment of the Sphinx’s stone headdress that had fallen into the dark. Vyse found no chamber, but he was not the first to cut into the body. A wide crack runs across the Sphinx’s waist, in places more than six feet across, possibly a natural flaw the builders worked around by lengthening the lion’s body. At some point, the crack was widened and shaped by human hands. Baraize later walled it off with brick and fitted it with iron bars, limestone, cement, and a second iron door.
A third opening lies beneath the chest, directly behind the Dream Stela, near the spot where the Sphinx was said to have spoken to the sleeping prince. Baraize sealed this one as well with cement, an iron beam, and a third door. Near the northern hind paw, another pit about six feet deep contains a single block of polished black basalt at its bottom. No one has established who placed it there or why.
Baraize published almost nothing about these features. No full report or measured drawings exist of what lay beneath his hidden doors. What remains are photographs and a layer of gray cement. A fourth opening was the one he reportedly hid most carefully. In 1980, Hawass and American archaeologist Mark Lehner were working at the Sphinx when three retired employees of the antiquities service approached them. As boys in 1926, they had carried baskets of sand for Baraize and recalled a hole or passage at the rear of the monument, near the tail, at ground level. One of them described its round opening precisely. No report and no map mentioned it. When a small slab was moved, the men found gray cement beneath it, then a narrow, roughly cut tunnel descending into the bedrock. Inside, the passage divided into two branches: one curving upward into the body of the Sphinx, the other descending about fifteen feet below the courtyard floor. Tool marks indicated it had been dug from the top down, in the manner of Egyptian tomb shafts. The upper end was sealed with large stone slabs from an early restoration. The tunnel ended where the bedrock became damp, at the water table. The question of what the water moved through was never answered.
The Sphinx sits in a horseshoe-shaped quarry cut into the bedrock, with the statue left in the center and carved from the remaining mass. Some of the removed stone was used in a nearby temple that also bears no inscriptions. Around the equinoxes, the setting sun aligns with the temple’s axis, passing the Sphinx’s shoulder before setting near the Second Pyramid. The monument stands near the eastern edge of the plateau, close to where the desert once met the Nile floodplain.
A separate site nearby demonstrates how deep the Giza builders could cut. A shaft beneath the causeway leading to the Second Pyramid descends about 100 feet through three levels into the bedrock. At the bottom lies a chamber cut into natural rock, with remnants of pillars and a stone sarcophagus surrounded by groundwater. Known today as the Osiris Shaft, it was noted in the 1930s but not fully explored until 1999, when pumps finally cleared the water. Its proximity to the Sphinx has raised the question of whether a similar structure exists beneath the monument itself.
In 1987, a team from Waseda University in Tokyo, led by Sakuji Yoshimura, conducted electromagnetic surveys around the Sphinx. Their results suggested possible cavities near the hind paws, features resembling a passage beneath the body, and a groove on the side that appeared to extend downward. The same year, officials spoke publicly about drilling a narrow hole and lowering a camera, a method that had just revealed a dismantled wooden boat at the foot of the Great Pyramid. No public results of such a camera survey beneath the Sphinx were ever released.
In 1991, geophysicist Thomas Dobecki and geologist Robert Schoch of Boston University conducted a seismic survey to measure weathering in the limestone around the Sphinx. Data from beneath the left forepaw indicated a cavity roughly 30 by 40 feet, beginning less than 16 feet below the surface. Dobecki described the shape as unusually regular, rectangular enough to suggest it was cut rather than natural. The survey also detected other anomalies along the southern side of the monument. The cavity was recorded, published, and broadcast in a 1993 television documentary narrated by Charlton Heston. No excavation has reached it.
A later team, supported by the Schor Foundation and Florida State University, received permission in 1996 to survey parts of the plateau with ground-penetrating radar and to conduct limited excavations. When they sought to extend their work, the permit was stopped. During the 1990s, the lower part of the Sphinx was refaced with new limestone blocks in a restoration completed in 1998. The work was needed, as earlier repairs were deteriorating, but it also placed the tail passage, the crack across the waist, and other openings behind fresh stone. The hidden doors remain closed, and access to the area near the paws now requires special permission.
The strongest geological objection to the idea of a hidden chamber is that limestone naturally contains voids, joints, and fissures widened by water over long periods. In 1978, a Stanford Research Institute team led by physicist Lambert Dolphin surveyed the Sphinx and dug into several anomalies, finding natural cracks rather than chambers. Dolphin concluded that no hidden chambers existed beneath the statue. When the later American team excavated one of its radar targets, it also proved to be a natural cavity. Seismic data is not a photograph, and a low-resolution survey can make an irregular natural void appear more geometric than it is. The 1991 work was designed to measure weathering, and critics argue the apparent cavity may have been heavily weathered or fractured rock. Limestone often fractures along straight joints, so nature can produce flat-sided voids. The southern anomalies may simply be a deeper extension of the large crack across the Sphinx’s waist.
In 2009, rising groundwater threatened the monument. Hawass oversaw the drilling of wells around the Sphinx to monitor and lower the water level. Workers encountered groundwater at about fifteen feet and installed pumps. They reported rock and water, but no chamber. Debris in the tail tunnel reportedly included modern materials such as cement, glass, and metal foil, suggesting recent visitors. The opening in the head may indeed be a socket for an added crown. The doorway depicted on the Dream Stela has a conventional explanation as a stylized palace facade, a common artistic motif in Egyptian funerary and sacred imagery.
The most dramatic version of the story, that a hidden hall of records left by a lost civilization lies beneath the paws, rests on no verified evidence. The prediction made by American psychic Edgar Cayce in the 20th century that such a chamber would be opened around 1998 did not come to pass. There is no confirmed chamber under the Sphinx.
What remains is a set of documented facts that do not fully connect. A statue with a sealed shaft in its skull. A fragment of its headdress found in a hole drilled into its back. Three hidden doors and a tunnel linked to an engineer who left few written records. A passage descending to groundwater beneath the tail. An anomaly under the left paw that a professional geophysicist described as unusually regular in shape. The most direct tests near that location have been narrow wells, which sample a single line of rock and cannot reveal the shape of anything surrounding them.
The technology to search more thoroughly already exists. Researchers have used muon detectors, which measure particles arriving from the upper atmosphere, to identify hidden voids inside the Great Pyramid without moving a single block. No comparable high-resolution survey of the bedrock directly beneath the Sphinx has been announced.
Across centuries, attempts to enter the monument or reach below it have been made by priests, pharaohs, treasure hunters, soldiers, engineers, and physicists. Each generation dug a little deeper, and each sealed its openings afterward. No one digs in one place that many times without a reason. The reason remains unknown.
