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A new study measuring vibration frequencies throughout the Great Pyramid revealed how it has been able to withstand severe seismic shocks.

The Great Pyramid Pyramids of Giza, Cairo, Egypt

Seismologists analyzed vibrations in the various chambers of the Great Pyramid of Giza to discover how the 4,600-year-old structure remains stable in the wake of disasters.Jonathan RashadByTaylor Mitchell BrownPublished May 21, 2026

Around 2500 B.C., Egypt’s great pharaoh Khufu began a massive construction project.

His goal was to erect a large pyramid on the Giza Plateau, which would later serve as his tomb, alongside a series of smaller pyramids for his wives. For 26 years, thousands of laborers hauled and stacked over 2.3 million limestone and granite blocks to create the 481-foot-tall monument. For millennia, the architectural marvel would endure the ravages of time.

Now, scientists have found that Khufu’s Great Pyramid was well-structured to withstand another kind of scourge: earthquakes.

In a study published Thursday, researchers from Egypt and Japan gathered resonance data, or vibrating waves, from nearly 40 different areas within and around the Great Pyramid to see how the monument responded to seismic activity. They found that the structure has a remarkable ability to disperse seismic vibrations, giving it a rock-solid response to otherwise destructive quakes.The data indicate the pyramid was “intelligently balanced and well-tuned” for stability, says Asem Mostafa, a seismologist at the National Research Institute of Astronomy and Geophysics (NRIAG) in Cairo, and an author of the study.

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Over the pyramid’s 4,600-year-long history, it has survived numerous earthquakes that have decimated nearby buildings. The findings, which were published in the journal Scientific Reports, add a new dimension to the already staggering ingenuity of ancient Egyptian engineers. While the research shows the builders' impressive abilities, the researchers state that they cannot say for certain whether their techniques were used with earthquakes in mind.

“We see this as the culmination of centuries of Egyptian builders learning from both successes and failures,” says Mostafa. “It felt like uncovering a masterpiece of empirical engineering that had been hiding in plain sight for thousands of years.”

Enduring Egypt’s earthquakes

Egypt is no stranger to seismic activity. Over the past few centuries, a handful of earthquakes have struck near Cairo with calamitous consequences. In October 1992, a magnitude 5.9 earthquake struck about 20 miles southwest of Cairo, devastating the plateau. It damaged or destroyed more than 129,000 buildings, including over one-third of the local houses. Many ancient mosques suffered cracks in marble structures. Tombs in the Valley of the Kings were damaged enough to require new bracing for internal support.

But only one stone fell from Khufu’s pyramid, according to Mohamed ElGabry, a seismologist also at NRIAG and lead author of the study.

“Ancient structures, built with massive, well-interlocked stone blocks, generally suffered far less damage than later era monuments,” ElGabry says.

Many of the Great Pyramid's advanced architectural features were already known to researchers, he adds. The monument is widest at its base, which spans over 755 feet, providing structural integrity that prevents it from toppling easily. It is also highly symmetrical and utilizes a firm bedrock foundation.

“The fact that it is structurally resilient was never in doubt,” adds Mostafa.

Much of the ingenuity came from a history of pyramid-building innovations. Earlier structures were built in the city of Saqqara, which is around 19 miles south of Cairo. The Pyramid of Djoser—also called the Step Pyramid—is the oldest of these and preceded the Great Pyramid by over a century. It has a different external shape from Khufu’s pyramids, rising in a chunky, stepwise fashion rather than a continuous slope as at the Giza Pyramids.

The pharaoh Sneferu, Khufu’s likely father, who ruled from 2613 to 2589 B.C., later built large pyramids that pioneered the smooth-sided shape of the Giza Pyramids. Ancient Egyptians continued to build pyramids long after Khufu’s death in 2566 B.C. While some of these pyramids utilized the same structural plans as his, others tried to cut costs.

(Making sense of the pyramids’ enduring mysteries)

Khufu’s son and successor, Djedefre, built a pyramid north of Cairo that partially utilized a hill to increase its prominence. The embedded monument minimized interlocking blocks, reducing its stability. The so-called “Black Pyramid,” built by Amenemhat III several centuries later, was constructed primarily of mud-brick, which was cheaper and more prone to deterioration than solid limestone blocks. The weaker base material led to their more rapid degradation due to erosion and aging. Unlike the Pyramid of Khufu, some of these structures have since collapsed completely.

Pyramid in sync

During their examination of the Great Pyramid of Giza, the seismologists measured vibration frequencies within its internal chambers and tunnels, including the King’s Chamber, Queen’s Chamber, relieving chambers, and Subterranean Chamber. They used a non-destructive technique called “ambient vibration analysis” that allowed them to measure how vibrations channel through the different blocks, tunnels, and internal cavities. The data would help them clarify how the structure responds to earthquakes.

Their results showed that the overall resonance throughout the structure averages between 2 and 2.6 hertz, indicating that vibrations reverberate evenly from stone to stone—a key sign of stability. The analysis also found that the vibrations differ from those in the soil surrounding the pyramid, which are around .6 hertz.

"The dominant vibration frequencies of the pyramid differ significantly from those of the surrounding soil, which likely reduces resonance effects during earthquakes,” says Mostafa. By reducing the resonance, the destructive potential of violent vibrations in the earth is minimized.

Ahmed Eldosouky, a geophysicist at Suez University in Egypt who was not involved with the research, agrees.

“The measurements across many internal parts of the pyramid showed relatively consistent fundamental frequencies,” Eldosouky says. “That level of dynamic homogeneity suggests a remarkably stable structural system, especially considering the monument’s age and construction period.”

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The researchers also found that the relieving chambers helped reduce destructive frequencies in the King’s Chamber, which lies directly below them. The frequencies decreased in these chambers, which helps settle seismic activity around the precious King’s Chamber and helps prevent the structure from sustaining damage in the event of an earthquake.

According to Mostafa, the new discovery shows that ancient Egyptian builders developed highly effective construction practices over generations of careful observation and refinement. "Their achievements remain extraordinary even when examined using modern scientific tools," he says

Cheering crowds, fast horses, dramatic accidents, and even a little sorcery made up a typical day of chariot racing in Rome as thousands flocked to watch their favorite spectator sport.

NO HOLDING BACKA chariot race in Rome’s Circus Maximus, depicted in a relief from the second century. Archaeological Museum of Colfiorito.SCALA, FLORENCEByMaría Engracia Muñoz-SantosPublished May 26, 2026

According to Livy, Rome’s Circus Maximus—the hippodrome nestled between the Palatine and Aventine Hills—was the site of the mythical rape of the Sabine women, a tragic event in Rome’s founding legend. The newly established, predominantly male state was facing a demographic crisis. After having his requests of intermarriage rejected, Romulus, Rome’s mythical founder, invited the Sabine people to the Consualia, a festival for the harvest god. Romulus distracted his audience with a dramatic chariot race that would allow the Romans to abduct the young Sabine women.

Although there is no evidence to support Livy’s account, we know the valley had been used for races and other spectacles for many years when King Tarquin the Elder first began to develop the stands of the Circus Maximus in the sixth century B.C. This hairpin racetrack would, after successive expansions, become the largest structure in the entire Roman Empire. According to ancient sources, at its peak, its stands could accommodate an audience of 250,000 spectators, a quarter of the city’s population. The vast arena provided a venue for all kinds of spectacles, from athletic races and pugilatus (boxing) to staged military combat and battle reenactments, gladiator fights, and even wild beast hunts. But what really drew the crowds was chariot racing.

A charioteer has just rounded the end of the spina, where spectators cheer him on. Oil painting by Alexander von Wagner, 1872–73, Manchester Art Gallery.BRIDGEMAN/ACI

Games were put on in the circus to coincide with particular religious festivals or under the sponsorship of a patrician—a member of Rome’s elite ruling class—eager to boost his popularity. In the first century B.C., there were 17 circus days in Rome each year, a figure that by the fourth century A.D. had risen to 66. The norm, at least from the middle of the first century A.D., was for 24 chariot races to be held on each circus day.

A terra-cotta fragment shows a charioteer mid-race. — COUNTING LAPSA terra-cotta fragment shows a charioteer mid-race and the dolphin sculptures used to mark laps by being lowered. Louvre Museum, Paris.RMN-GRAND PALAIS

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The charioteers (aurigae), usually enslaved people or freedmen, and the chariots themselves belonged to the so-called factiones, professional teams hired by the event organizers. Each faction was managed by a senior charioteer, called a dominus factionis, and employed a specialized staff in charge of selecting and caring for the horses, building the chariots, and assisting the competitors during the races. The teams were distinguished by their colors. At first there were only two: red and white. Then, under Augustus, a blue team was added, and later, a green one too.

The inaugural parade

The spectacle began with an opening procession, called a pompa circensis, at Capitoline Hill, which then crossed the Forum along Via Sacra and turned toward the Forum Boarium (cattle market) by the Circus Maximus. It was an impressive, noisy, colorful march, with members of the nobility and the state authorities participating alongside the charioteers, accompanied by musicians, perfume carriers, and statues of various divinities. Each of the factions would display their colorful emblems.

Charioteers from four factions who competed in the chariot races. — Charioteers from four factions competed in the chariot races. Mosaic from imperial times. National Roman Museum, Rome.ALBUM

The Circus Maximus’s track measured between 1,800 and 1,900 feet long and around 250 feet wide; in other circuses in the provinces, the tracks tended to be much smaller. Sand was placed over compacted earth to form the surface of the arena. Running down the central section, a low dividing wall some 1,100 feet long was known as the spina (backbone). It was flanked by small ponds, shrines, and statues of gods as well as an obelisk brought from Egypt after its conquest by Emperor Augustus. In the fourth century, a larger obelisk was erected. At either end of the spina were the metae, each composed of three cones, sometimes gilded in bronze and used to mark the turning points and the finish line. Victory belonged to the charioteer who took the final turn.

The track record of a star charioteer

A mosaic depiction of chariot racing. — One of the mosaics in the Roman villa of Casale, in Sicily’s Piazza Armerina, includes this depiction of chariot racing.BRIDGEMAN/ACI

Charioteers enjoyed celebrity status, as did some horses. An inscription on the tombstone of Diocles, a famous charioteer of his time, gives the details of his life as recorded by his fans, who erected the stone. Although the original stone has been lost, several copies have been preserved. The inscription explains that Diocles was born in a Roman province in Hispania (today’s Iberian Peninsula) in A.D. 104, and that he competed from the age of 18 until his retirement at 42. (Other champions, like Scorpus, weren’t lucky enough to survive until retirement). Over the years, he represented three of Rome’s four factions and amassed a phenomenal track record, participating in 4,257 races, with 1,462 victories and placing second 861 times and third 576 times. His total prize money amounted to more than 35 million sesterces, which is around $800 million in today’s money.

The four-horse favorite

Several types of chariots were used for racing: bigas were pulled by two horses and trigas by three. Occasionally chariots might be pulled by up to ten horses. But, without doubt, the crowd’s favorite competition was that of the quadrigae, pulled by four horses. These horses were selected for their appearance and strength, and it was important to harness them in the correct order for maximum speed. The two middle horses were attached to the shaft of the chariot, and the two on the outside were attached simply by a strap. The horse running on the side facing the spina had to be the strongest and fastest to both lead and steer. The single-axle carriages were small, weighing only 55 to 65 pounds. The front portion of the wooden frame was covered in leather, and small wheels minimized the risk of flipping over.

The slope of the stands and central spina are visible at the modern-day Circus Maximus site. — THE CIRCUS MAXIMUSThe slope of the stands and central spina are still visible at the Circus Maximus site today. The tower in the foreground dates to medieval times.SHUTTERSTOCK

Some races had two or three chariots in each of the factions, which meant there could be up to 12 chariots on the track at a time. But the races that most stirred the crowds were those with only one chariot per team. The races were generally run over seven laps and lasted only eight to nine minutes, with 10 or 12 races held per day. Caligula doubled that number, putting on 24 races a day during the games at the end of his reign.

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The Circus Maximus

The Circus Maximus, reconstructed here as it would have been in its heyday, served as a model for circuses in other cities across the Roman Empire. Sixth-century writer Cassiodorus conjectured about the possible meaning of its design. He thought the track symbolized the earth, and the water-filled
moat of the spina represented the sea. The obelisks decorating the spina represented the great stars. The twelve carceres (starting gates) he thought were linked to the signs of the zodiac or months of the year. The chariots made seven laps around the track in a counter-clockwise direction, echoing the seven days of the week. And the four teams (red, white, blue, and green) represented the seasons of the year.

The carceres, or the twelve starting boxes, are pictured. — The carceres were the twelve starting boxes, three for each team, where the chariots were placed before the race. To ensure a fair start, they were closed off by double doors that opened the moment the editor started the race by dropping a white cloth (mappa) from his tribune, located on the Porta Pompae. The row of carceres was arranged in a curve to minimize the advantage that any one chariot would have when entering the first straight.AKG/ALBUM

A rousing start

Before the race, the chariots and horses were enclosed in the carceres: starting boxes with gates opening onto the track. A team’s station was decided by lot: Balls in the team colors were drawn out of a kind of drum and the faction whose color came out first could choose its starting position, lending it an advantage.

The highest authorities in Rome, including the emperor, would watch the spectacle comfortably seated in a tribune called the pulvinar, which afforded a magnificent view of the action. The editor, the spectacle’s sponsor, used a box above the carceres. He was the one who started each race by dropping the mappa, a white cloth, to the ground. As the mappa fell, a four-foot-long, trumpetlike instrument called a tuba was sounded simultaneously, a signal to the public and the competitors that the race was starting. A mechanism immediately released the doors of the carceres and the chariots burst forth into the race.

A charioteer wears the horses’ reins tied around his waist. — A DANGEROUS PURSUITEach charioteer wore the horses’ reins tied around his waist, a practice that increased the risk of being dragged along in an accident. Detail of The Chariot Race by Alexander von Wagner, 1872–73.BRIDGEMAN/ACI

In his epic poem Punica, Silius Italicus describes a chariot race that took place in Hispania. “Even before the starting gate was unbarred, the excited crowd surged to and fro with a noise like the sound of the sea, and, with a fury of partisanship, fixed their eyes on the doors behind which the racers were standing. And now the signal was given, and the bolts flew back with a noise. Scarcely had the first hoof flashed into full view, when a wild storm of shouting rose up to heaven. Bending forward like the drivers, each man gazed at the chariot he favored, and at the same time shouted to the flying horses.”

The charioteers tried to keep close to the spina in order to minimize the distance covered, although this made maneuvering the turn at each end of the track more difficult. Many tried to stay in first position throughout the race, but others preferred to wait until the later laps, or even the final straight, before making a sprint to victory.

Sorcery and skulduggery

A lead sheet is inscribed with a curse and fixed with two nails. — CURSE TABLETAt left, a lead sheet (lamella) is inscribed with a curse and fixed with two nails. First century B.C.RMN-GRAND PALAIS

Fans of chariot racing were highly invested in their chosen team. Many placed bets on the winning chariot, with gambling being an integral part of the experience. Some resorted to the black arts in a bid to jinx the rival teams. Archaeologists have found curse tablets made of lead sheets that call on wandering spirits to unleash misfortune on the opposing factions, rolled or folded, pierced with a nail, and left in the crevices of tombs or in the circus itself, waiting for the spirits to do their dirty work. Even charioteers themselves were suspected of witchcraft. According to historian Ammianus Marcellinus, one was condemned for having his son trained in black magic; another competitor was accused of practicing sorcery and burned at the stake.

As dust kicked up during the race, it could cause the charioteer to become disoriented. A member of his team on horseback, the hortator, would serve as a guide and shout out the position of his opponents. Other team members, the sparsores, ran onto the track to throw refreshing water over the horses.

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Wrecks

Horrendous and sometimes fatal accidents, or naufragia (shipwrecks), as the Romans called them, happened regularly during chariot races. The most dangerous moment for a charioteer was either overtaking another chariot or making the tight turn at the ends of the spina. Given the speed of the vehicles (over 45 miles per hour on the straights and at least 15 to 20 miles per hour on the turns), the charioteers ran a serious physical risk. For protection, each charioteer wore a metal helmet and kept a dagger tucked into his girdle that he could use if he needed to cut the reins tied around his waist. That move would allow him to avoid being dragged along the ground by his horses and potentially trampled by the other competitors’ horses.

PRIZE FOR THE WINNERThe winner of the race, from the red faction, holds the victory palm. Third century A.D., National Archaeological Museum, Madrid.RMN-GRAND PALAIS

The excitement reached a fever pitch when the winner crossed the finish line in front of the judges’ stand. The tuba sounded again to announce the victory. The charioteer was then presented with a palm and a laurel wreath as a symbol of his triumph as well as a cash prize. Finally, he made a victory lap of honor around the spina to receive the adulation of the crowd. The public would take advantage of this interval to relax, eat, or chat with companions, waiting for the next show to begin, whether athletics, a wild beast hunt, or another exhilarating chariot race.

The thrill of the race

A mosaic depicts various stages of a chariot race. — A mosaic depicts various stages of a chariot race in the circus, or hippodrome.COURTESY FRYNI HADJICHRISTOPHI, EXCAVATION DIRECTOR, DEPARTMENT OF ANTIQUITIES, CYPRUS

An exceptional mosaic was first discovered in 1938 in Akaki, on the island of Cyprus, but not thoroughly excavated until the 2010s. Dating to the first half of the fourth century, it decorated the floor of a room in a large Roman villa and depicts various stages of a chariot race in the circus, or hippodrome. Chariot racing was the island’s favorite sport, as it was throughout the Roman Empire. This mosaic’s central panel, measuring 36 feet long by 13 feet wide, is one of only nine found within the empire depicting a chariot race. In terms of its size and preservation, it’s comparable to mosaics with the same theme found in Sicily, Lyon, Madrid, and Barcelona. The Akaki mosaic is detailed and precise in its depiction of the circus, showing the elongated track with its central spina, a water channel embellished with small monuments, and even the lap counter, decorated with ova (eggs).

At one end is the finish line, with three cones placed atop a platform. The chariots, or quadrigae, are depicted in a highly realistic style; even the emblems of each team can be seen on the charioteers’ clothing. Next to the chariots, we see the hortatores, riders who shouted instructions to the charioteers, and the sparsor, who refreshed the horses with water. The complete panel of the mosaic, of which a little more than two-thirds is visible here (the rest is quite deteriorated), depicts a race with four chariots, one from each faction. The ancient Greek inscriptions include two names for each quadriga, one for the charioteers (Damasos, Polyphemus, Kosmion, and Protogenes) and one for the leading mares (Telonike, Leneo, Pegasus, and Thalanto). The winning charioteer in this competition was Protogenes, who, like his competitors, is depicted in several moments: from race to victory, when he receives the coveted palm.