The Menga Dolmen. Image credits: Grez/Wikimedia Commons

“Megaliths represent the earliest form of monumental stone architecture,” write the authors of a 2024 study, and the Menga Dolmen is a fantastic example. This prehistoric megalithic structure near Antequera in southern Spain stands as one of the most impressive and enigmatic monuments of Europe’s distant past.

This ancient stone chamber, covered by an earthen mound, was made using massive slabs during the Neolithic period. It has remained standing for almost 6,000 years. Menga is more than 1,000 years older than the Great Pyramid of Giza and predates Stonehenge’s famous great-stone phase by roughly the same amount. Many modern buildings, by comparison, require substantial maintenance or reconstruction to survive a fraction of that time.

So then how come people in the Neolithic era made an artificial stone chamber strong enough to last for 6,000 years, and that too without modern machines like mechanical cranes and reinforced concrete? Recent research attempts to answer this question.

“These people had no blueprints to work with, nor, as far as we know, any previous experience at building something like this, and yet, they understood how to fit together huge blocks of stone with a precision that would keep the monument intact for nearly 6,000 years,” Leonardo García Sanjuán, one of the study authors and an archaeologist from the University of Seville in Spain, told Nature.

Neolithic Science

A dolmen is a chamber built from large upright stones supporting one or more roof slabs. These stone structures were commonly covered by mounds of earth and smaller rocks, known as tumuli. Dolmens frequently held human remains, but Menga’s original purpose is not entirely clear. It may have served as a communal burial place, a ceremonial gathering space, or both. There is no firm evidence that it was built specifically as a tomb for a ruling family.

But in this study, the focus wasn’t the people, but rather the engineering.

Menga Dolmen is made of heavy stones attached and placed together with great precision. For instance, the largest stone that makes the roof of the structure weighs 150 tonnes. That’s as heavy as a blue whale and five times heavier than the largest stone used in Stonehenge. 

Working with such huge blocks of stone requires a basic understanding of geology, engineering, geometry, and architecture. 

“You see that these people knew about physics, friction, angles. They knew about geology. They knew the properties of the rocks, they knew about geometry,” García Sanjuán told CNN. 

“Put these things together what do you have? We have to call it science. We’ve never talked about Neolithic science before only because we are too arrogant to think that these people could do science the way we do it,” García Sanjuán said.  

Image via Wiki Commons.

Today, the Menga Dolmen forms part of a UNESCO World Heritage Site and is one of the largest known megalithic monuments in Europe. Its 32 large structural stones collectively weigh an estimated 1,140 tonnes. The 2024 researchers studied laser scans, stone angles, geological features, excavation records, diagrams, and historical photographs to reconstruct the sequence in which the monument may have been built.

The making of a long-lasting megalith

The reconstruction builds on a separate geological study published in 2023. That research traced most of Menga’s stones to outcrops at Cerro de la Cruz, approximately one kilometer from the construction site and uphill from it. The rocks are mostly calcarenites: relatively soft sedimentary stones that were easier to shape than harder rock, but also fragile and vulnerable to cracking and water damage.

The researchers propose that workers dragged the stones downhill on large wooden sledges, probably over carefully prepared wooden trackways. No wooden equipment survives, so this remains a reconstruction based on the terrain, the stones’ geology, and experimental archaeology rather than direct evidence of the transport system.

The Menga Dolmen from inside. Image credits: Pedro J Pacheco/Wikimedia Commons

At the construction site, the builders excavated a large foundation box directly into the bedrock. Some of the upright stones were embedded as much as 3.2 meters below the monument’s eventual floor, leaving roughly one-third of their total height underground. The researchers propose that ramps, ropes, wooden structures, and counterweights allowed workers to lower the enormous stones gradually into their sockets.

Each block was carved to have a slight incline and fit exactly with the adjacent stones. This resulted in a highly stable self-supporting structure with interlocked stones reinforcing one another. 

“This technique, aimed at achieving a smooth and gradual tilting of the stones into the sockets, was crucial as this allowed the placement of the stones with millimetric precision, both inside the sockets as with regard to the stones standing next,” the study authors note.

Credit: Scientific Reports (2023). DOI: 10.1038/s41598-023-47423-y

Using this carefully planned approach, the makers first created the walls and pillars and then placed heavy capstones above them to form the roof. 

“Once the capstones were added, it was like a solid box, with the bedrock still inside, and then they carved away all that rock, all that bedrock, to make the chamber,” García Sanjuán added.

Only after the roof was in place did workers remove the remaining bedrock and earth from inside, exposing the chamber beneath the stones. Finally, they covered the monument with a mound of soil and smaller rocks. The mound added structural support while also limiting water infiltration and protecting Menga’s relatively soft stone from weathering.

The monument’s location was also carefully chosen. Menga stands on stable ground near the quarry, allowing the stones to be transported downhill rather than hauled upward. Its central axis points toward La Peña de los Enamorados, an imposing mountain whose profile resembles a reclining human face. This is highly unusual: most Iberian megaliths were oriented toward the sunrise rather than such a prominent natural landmark.

If that wasn’t impressive enough, the Antequera region experiences seismic activity. By setting the uprights deep into bedrock, locking them against one another, and supporting the roof with internal pillars, the builders created a structure unusually resistant to ground movement. The researchers cannot establish whether earthquake resistance was an explicit objective, but the design has helped the monument survive both tremors and the gradual movement of the ground.

A monument people kept returning to

Menga’s story did not end when the Neolithic communities that built it disappeared. A study published in 2026 examined two adult men who were buried in the monument’s entrance area between the eighth and eleventh centuries C.E. By then, Menga was already around 4,000 years old.

The men had been placed in carefully arranged graves aligned with the dolmen’s central axis, suggesting that their burial at Menga was deliberate rather than accidental. Although their exact religious identities remain uncertain, they lived during the period of Al-Andalus, when much of southern Spain was under Muslim rule.

DNA was too degraded for a complete analysis of both men, but researchers recovered useful genetic information from one. His ancestry included Iberian or wider European, North African, and Levantine-related components, reflecting the movement and mixing of populations in medieval southern Spain.

The burials reveal that Menga remained a meaningful place thousands of years after its builders were gone. Its precise original function may never be known, and it probably changed over time. But the monument’s extraordinary engineering ensured that successive communities could continue to encounter, reuse, and reinterpret it.

The study is published in the journal Science Advances.

This article was originally published on September 5, 2024, and has been edited for style and to include more information.