There are many hypotheses about the construction of Stonehenge, but we continue to ask ourselves the same question: How was such a monument built in ancient times? There are many archaeologists who choose to look much further back in time for the necessary clues, and now a new study looks to shed light on engineers’ understanding of the past. The piece was in Spain. In a magnificent stone monument built 1,000 years ago.

Menga dolmen. Located in Antequera, Spain, we are faced with one of the most impressive and ancient megalithic monuments in Europe, dating back to 3,500 BC. The importance of this monument lies in its great size, with a 25-meter-high burial chamber built with huge stones, weighing tons, and with its unusual orientation towards the Pena de los Enamorados, a distinctive feature among dolmens that are usually aligned with the solar events.

But it is unique, a masterpiece of prehistoric architecture. Let’s consider for a moment that their total weight is around 1,140 tons, heavier than two Boeing 747s loaded with passengers. That’s part of the mystery and magic of this type of construction, and a new study sheds light on the knowledge available for the construction of similar works.

New study. The analysis, by a team of archaeologists published a few days ago in the journal Science Advances, revealed that the structure was built with an extraordinary level of scientific understanding. “I have always been amazed by the engineering skills required to build this dolmen,” says Michael Parker Pearson, an archaeologist at University College London. “The work reveals how precise it had to be, with extraordinary perspectives on size and angles. With such large stones, they could not have afforded any mistakes in getting them into position.”

“Going inside and contemplating such a huge Neolithic monument made me curious to learn more about this dolmen,” says José Antonio Lozano Rodríguez, a geologist at the Spanish Oceanographic Institute and first author of the study. “What struck me most about the Menga dolmen was its monumentality.”

Re-enactment of the proposed placement process of the obelisks

How to move tons of stone? What the researchers apparently did was dive into what’s known as a geoarchaeological analysis of the site, examining laser and image scans from previous excavations and ethnographic descriptions of the area’s construction techniques and topography.

After collecting the data, the team came to an unknown conclusion: the construction process of Neolithic engineers. They started from known facts. For example, a previous study had already determined that the stones came from a quarry located a kilometer away, at a strategically higher altitude than the Menga dolmen. Like? It is thought that the builders transported the stones using sleds on a rail made of wooden beams, implying knowledge of friction, acceleration and center of mass.

Reconstruction of the proposed placement process of vertical stones inside the dolmen

Carve the stones, key. As detailed, once on site, the stones that formed the walls and columns were placed upright in deep recesses, so that one-third of each stone remained underground. They suggest that the builders probably achieved this by using counterweights and ramps to account for the relatively soft (and therefore easily damaged) nature of the sandstone rock.

The study suggests that the walls were carved to interlock and support each other, thus increasing the structure’s stability. “These people had no plans to work together, nor, as far as we know, had any prior experience building something like this,” said Leonardo García Sanjuán, an archaeologist and co-author of the study from the University of Seville. “There’s no way you can do this without at least a basic understanding of the science.”

First time broadcasting. The researchers’ work highlights that the walls lean slightly inwards, forming angles between 84/85 degrees, so that the upper part of the room is narrower than the lower, crooked part. In this context, the largest of the five capstones was hollowed out to increase stress distribution, creating a simple arch with its center higher than its sides.

This is by no means insignificant. According to the study, “To our knowledge, this is the first time in human history that the beginnings of the arch have been documented.” They then excavated the soil inside to lower the floor level of the chamber, while the outside was covered with soil to further insulate and strengthen the structure.

Solution. The findings represent a pre- and post-modern understanding of architectural knowledge in the Neolithic period, helping to understand not only how the Menga dolmens were built, but also later artefacts and monuments such as Stonehenge itself or the step pyramid of Djoser.

That’s why the expert team has no other word to describe the management of all these concepts. “We should call it science. We never talked about Neolithic science before, because maybe we were too arrogant to think that these people could do it the way we did.”

In fact, as García Sanjuán assured CNN, “if any engineer today tried to build Menga with the resources that existed 6,000 years ago, I don’t think they would be able to do it.”

Image | Pexels, Leonardo García Sanjuán, José Antonio Lozano Rodríguez et al, Science Advances

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