Stonehenge: Neolithic People Moved Enormous Rocks Using Pig Fat for Lubrication, Archaeologist Says

Stonehenge's enormous rocks may have been transported to the prehistoric site with the help of pig fat, a scientist has said. Archaeologist Lisa-Marie Shillito say residues of fat on pottery discovered near the monument suggest Neolithic people greased the sleds used to move the huge stones with lard.

Construction of Stonehenge began about 5,000 years ago. Its exact purpose is unknown, although there are many theories, including that it was intended to be a burial ground and space for religious ceremonies.

It has long been known that many of the rocks used to construct Stonehenge did not come from the site. The largest of the stones, known as the sarsen trilithons, are over 25 feet in height and weigh over 30 tons. These were moved from a site 18 miles away. The smaller "bluestones" came from quarries 160 miles away in west Wales. It is thought that the Neolithic people used sleds to roll them along.

In a study published in February, researchers examined how the stones were quarried. They suggested the Neolithic people may have constructed a platform to excavate the rocks, then used wooden levers to lower the rocks onto a wooden sledge that could then have been "hauled away with ropes."

The largest of the stones, known as the sarsen trilithons, are over 25 feet in height and weigh over 30 tons. These were moved from a site 18 miles away.

Researchers have also previously suggested these sledges were greased to help move them along—past experiments show the most efficient way to transport them would be a greased timber slipway. However, physical evidence to back this up was lacking—the logs used for the sledges are unlikely to have been preserved.

In a study published in Antiquity, Shillito, from the U.K.'s Newcastle University, has said fat residues found on pottery near Stonehenge may help back the greased sled theory.

The residue of pig fat has generally been attributed to cooking—the surrounding Neolithic sites are known to have been used for great feasts attended by hundreds of people. However, Shillito suggests the fragments discovered appear to have come from bucket-shaped vessel rather than one used for cooking. This indicates the buckets were used for the collection and storage of tallow—a form of animal fat. She says the fat could then have served two purposes—cooking and grease to move the huge stones.

"Cooking/food has usually been the default assumption in archaeology when analysing pottery residues," she told Newsweek. "It's the most obvious explanation and often correct, but sometimes things are a bit more complex and it's important not to stick with the immediately obvious and consider other possibilities. In this case it could be a 'dual purpose'—cooking and collecting the fat as a by-product. I had the idea as the amount of fat we found in these pots was unusually high, the only comparable examples being in oil lamps."

Shillito also said animal bones at the site suggest pigs were cooked via spit roasting, rather than being chopped up and stewed in the pots—giving more weight to the idea the fat was collected for another purpose.

Concluding, Shillito says much of what we know about Stonehenge is based on assumptions and interpretations—and that evidence from the site should be placed into a wider context using a multi-pronged approach that includes alternative ideas, as this will help build a better overall picture of the site and how it was being used.

Stonehenge's construction, she adds, is no longer a mystery: "There is so much evidence now showing how it could have been done. Live modern experiments, ethnographic examples of people moving megaliths, and now we have evidence for the lubricant that would have been used in the Neolithic. The only thing we don't have is the sleeper and sledges being preserved—as these would have been wood which doesn't preserve in normal conditions."

Neolithic people appear to have transported Stonehenge rocks using pig fat as grease. Matt Cardy/Getty Images