On the sun-drenched plains of southern Spain, a mystery carved in stone has captivated archaeologists for centuries. The Menga Dolmen, a prehistoric megalithic structure near Antequera, stands as one of the most impressive and enigmatic monuments of Europe’s distant past.

This ancient burial mound, made using massive stone slabs during the Neolithic period, has remained intact for a staggering 6,000 years. It is nearly 1,500 years older than the Great Pyramid of Giza and 1,000 years older than Stonehenge. 

This is quite shocking because despite having access to the most advanced construction tools and technologies, today’s engineers and architects can’t make structures that could last so long. 

For instance, even some of the best modern architectural marvels such as the Burj Khalifa, the Empire State Building, and the Sydney Opera House have an expected lifespan of only 100 to 250 years. 

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? A new study 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

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.  

Today, the Menga Dolmen is a UNESCO World Heritage Site and one of the world’s largest megaliths. It was made using 32 stone slabs that collectively weigh 1,140 tonnes. To study how it was built, the authors used laser scans and examined diagrams and photos of the structure from previous studies. Here’s what they found:

The making of a long-lasting megalith

The study reveals that the 32 stone blocks used to build the Menga Dolmen were excavated from a quarry located about a kilometer away from the construction site. The stones were transported using special wooden tracks.

The makers of the Menga Dolmen designed sockets with foundations reaching 1.5 meters deep at the construction site (into the bedrock). The stone slabs were carved and carefully fitted inside these sockets using ramps and counterweights. 

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.

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.

Finally, they covered the structure with a mound of soil and small rocks to provide good insulation and protect it from all types of weather. 

An important point to note is that Menga Dolmen is located near the city of Antequera, in southern Spain. This region experiences high levels of seismic activity. Given its robust construction, it is likely that the builders of Menga Dolmen may have designed it to withstand earthquakes. 

However, the study authors are still not sure if this structure represents a temple or a tomb. Hopefully, further research will reveal the answer to this question.

The study is published in the journal Science Advances.