The interior of the monument in Spain known as Menga Dolmen
Miguel Angel Blanco de la Rubia
Neolithic people appear to have understood sophisticated scientific concepts such as physics and geology and used this knowledge to build a megalithic monument in southern Spain.
The Menga Dolmen is one of the oldest megaliths in Europe, dating from between 3600 and 3800 BC. Its covered enclosure was constructed from 32 large stones, some of which are the largest used in such structures. The heaviest of these weighs over 130 tonnes, more than three times the weight of the heaviest stone at Stonehenge in Britain, which was constructed more than 1,000 years later.
“(In the Neolithic period) it must have been very impressive to see this building made of these huge stones,” says Leonardo García Sanjuán of the University of Seville in Spain. “It still moves you. It still makes an impression today.”
García Sanjuán and his colleagues have now carried out detailed geological and archaeological analyses of the stones to find out what knowledge Menga’s builders had to erect the monument in the town of Antequera.
Paradoxically, they found that the stones are a type of relatively fragile sandstone. While this means they have a higher risk of breaking, the team discovered that this could be compensated for by shaping the stones to form a very stable overall structure.
Neolithic people would have had to fit the blocks tightly together somehow, Garcia Sanjuán says. “It’s like Tetris,” he says. “When you look at the precision that was needed to do it and how well the individual stones fit together, you have to assume that they had some idea of angles, even if only rudimentary.”
The researchers also found that the 130-ton stone that was placed horizontally on top as part of the roof was shaped so that its surface rises in the middle and slopes down towards the edges. This distributes the force in a similar way to an arch, improving the strength of the roof, says García Sanjuán. “As far as we know, this is the first time in human history that the principle of the arch has been documented.”
Menga – whose purpose is unknown – is also oriented to create special light patterns inside at the summer solstice and its stones are protected from water damage by several layers of carefully rammed clay, further demonstrating the builders’ knowledge of architecture and engineering.
“They knew geology and the properties of the stones they used,” says García Sanjuán. “When you put all that together – engineering, physics, geology, geometry, astronomy – it’s something we can call science.”
There are Neolithic buildings in France that rival Menga in size, but how they were built has not yet been well researched, says García Sanjuán. “In its current form, Menga is unique on the Iberian Peninsula and in Western Europe.”
“The surprising thing about it is the level of sophistication,” says Susan Greaney of the University of Exeter in the UK. “The architectural understanding of weight distribution is something I have never seen before.” But she adds that this is perhaps less a testament to scientific understanding than to architecture and engineering.
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