The Great Sphinx of Giza contains several sealed openings that have raised questions for nearly a century. A metal hatch sits on top of the monument’s head, covering a square shaft roughly six feet deep cut into the skull. Workers discovered the shaft in the 1920s during a cleaning campaign led by French engineer Émile Baraize. Photographs from that period show a man standing inside the pit, which reaches about chest height on an adult.
That shaft was not the only opening. Additional cavities exist in the Sphinx’s back, beneath its chest, and near its tail. All of them were opened and later sealed with concrete and iron. Reports also describe a tunnel that does not appear on official maps, and survey data has suggested an anomaly in the bedrock beneath the front paws.
The Sphinx itself is one of the largest sculptures ever carved from a single block of living rock. It measures roughly 240 feet long and 66 feet high, shaped from the bedrock of the Giza plateau around 2500 BCE, most likely during the reign of Pharaoh Khafre. No inscription from its own era names the people who carved it or explains its purpose. The name “Sphinx” is Greek, applied about 2,000 years after its creation, while the Arabic name translates roughly as “father of terror.”
Ancient accounts described access to the interior. A granite tablet placed between the paws around 1400 BCE, known as the Dream Stela, records that the Sphinx spoke to the young prince Thutmose IV and promised him the throne if he cleared away the sand. In the sixteenth century, a German traveler reported that a priest climbed inside the head and spoke from within, leading people below to believe the Sphinx itself was talking. The Roman writer Pliny the Elder recorded a belief that a king was buried inside the monument.
When the sand was finally removed, the openings began to appear. In 1798, a French artist accompanying Napoleon’s campaign sketched men standing atop the Sphinx’s head, with one figure being pulled up from a hole. Baraize closed that particular opening in 1925, lining it with concrete and fitting a metal cover. The most common explanation is that the shaft served as a socket for a crown or other headdress added during the New Kingdom, when the Sphinx was worshipped as a living god. No crown has ever been found, however, and the shaft is deep enough to conceal a standing adult.
In 1837, British army officer Howard Vyse drilled into the Sphinx’s back using iron rods. The drill stalled at a depth of about 27 feet, and Vyse used gunpowder to free it. The scar remained visible for over a century. When archaeologist Zahi Hawass cleaned the cavity in 1978, he found a piece of the Sphinx’s own stone headdress inside. A natural crack in the rock crosses the Sphinx’s waist, wide enough in places to nearly split the monument in two. Human hands had widened the crack into a shaft at some point, which was later sealed with a brick entrance and iron door.
Another cavity sits directly behind the Dream Stela, beneath the chest. Baraize covered it with concrete and a third door. Near the northern hind paw, a cut about six feet deep holds a single block of polished black basalt. No record explains who placed it there or why. Baraize, who spent more than a decade on the most prominent excavation in Egypt at the time, published almost nothing about these openings.
In 1980, Hawass and American archaeologist Mark Lehner were mapping the Sphinx when three elderly former workers approached them. As boys in 1926, they had carried baskets of sand for Baraize. They remembered a hole near the tail at ground level. Moving a small slab, the team found concrete, and beneath it a narrow tunnel cut by hand with footholds in the walls. The tunnel split into two branches: one rising into the Sphinx’s body, the other descending about 15 feet below the courtyard floor. The passage stopped at groundwater. Who dug the tunnel remains unknown, but tool marks suggest it was cut from the top down, similar to ancient Egyptian tomb shafts.
The Sphinx sits in a horseshoe-shaped quarry cut into the bedrock. Workers left the central block and carved the lion from it. The removed stone was used in a nearby temple with astronomical alignments to the equinox. Near the Sphinx, a separate shaft descends roughly 100 feet through bedrock to a chamber containing a stone sarcophagus surrounded by groundwater. Known as the Osiris Shaft, it was not fully explored until pumps made access possible in 1999.
Several surveys have examined the bedrock beneath the Sphinx. In 1987, a team from Waseda University in Tokyo reported possible cavities near the hind paws and signs of a passage-like anomaly under the body. In 1991, geophysicist Thomas Dobecki and geologist Robert Schoch conducted seismic surveys. They found an anomaly beneath the left front paw: a void roughly 30 by 40 feet wide starting less than 16 feet below the surface. Dobecki described the shape as unexpectedly regular and rectangular, suggesting it could be man-made. The same survey indicated additional anomalies along the south side of the monument.
The results were televised in 1993 and attracted considerable attention. A subsequent American team received permission for limited ground-penetrating radar work in 1996, but the project was halted. During the 1990s, restoration campaigns covered the lower portions of the Sphinx with new limestone blocks, sealing the tail tunnel, the waist crack, and other features behind fresh stone. The official position has remained that no evidence confirms a man-made chamber beneath the Sphinx, and that the monument is too fragile for repeated invasive testing.
The strongest counterargument is geological. The Giza plateau is limestone, which commonly contains natural cavities, joints, and fractures widened by water over long periods. A 1978 survey by the Stanford Research Institute found several anomalies, and drilling revealed them to be natural fissures, not chambers. When the later American team excavated one of its radar targets, it also proved to be a natural void. Seismic data is not a photograph; a low-resolution survey can make an irregular natural cavity appear more geometric than it is. Limestone also tends to break along straight joints, so nature can produce flat-sided openings. In 2009, drilling near the front paws encountered groundwater at about 15 feet, along with rock and water, but no chamber.
Debris in the tail tunnel reportedly included modern materials such as concrete, glass, and metal fragments, suggesting relatively recent visitors. The shaft in the head may well be the crown socket described in textbooks. The entrance shown on the Dream Stela has a conventional scholarly explanation as a decorative palace facade frequently used in Egyptian art. Both early written accounts likely repeated rumors rather than direct observations.
Even after removing the more speculative theories, the documented record remains incomplete. A monument with a sealed metal hatch in its skull. A fragment of headdress found at the bottom of an old drill hole. Three hidden doors and a tunnel connected to an engineer who left few written records. A passage descending to groundwater. And a seismic anomaly beneath the left paw that a professional geophysicist described as remarkably regular.
The strongest subsequent drilling near that location has been narrow boreholes, which sample a single line through the rock and cannot reveal the shape of whatever surrounds them. More advanced scanning methods exist. Researchers have used muon detectors, which measure particles from the upper atmosphere, to identify hidden voids inside the Great Pyramid without moving a single block. No comparable high-resolution scan of the bedrock directly under the Sphinx has been announced.
For centuries, people have attempted to enter the monument or reach beneath it. Priests and pharaohs, treasure hunters and soldiers, engineers and scientists. Each generation dug a little deeper than the last, and each generation sealed its openings afterward. Some may have chased rumors. The rumors may have begun as memory of something known when the monument was new, later folded into stories about a voice, a burial, or a door, then lost under the sand. If so, the builders of Giza may have placed the Sphinx over something, and the historical record may be missing a chapter that lies about 16 feet beneath a stone paw.
The stone beneath the left front paw has never been lifted. It has been surveyed and recorded and closed over. It remains there, awaiting permission for someone to open it. Whether it contains a carved chamber or simply a geological formation has yet to be determined.
