Building the Stonehenge may not have been as difficult as previously thought, according to a new study which found that only 20 people were likely required to move the huge bluestones used in the World Heritage Site.
How prehistoric men managed to transport the huge rocks of Stonehenge over 220km from the Preseli Mountains in Wales to their final home in Wiltshire has baffled generations of experts.
Now, researchers at University College London found that mounting huge stones on a sycamore sleigh and dragging it along timbers required far less effort than was expected.
In their experiment, just 10 people were able to pull a one tonne stone along the make-shift silver birch track when moving at around 10 feet every five seconds.
The bluestones from Stonehenge weigh about double the experimental block, but it is possible that one huge stone could have been brought by a group of just 20 people, researchers said.
"We were expecting to need at least 15 people to move the stone so to find we could do it with 10 was quite interesting," said doctoral student Barney Harris, who conducted the trial.
"We know that pre-industrialised societies like the Maram Naga in India still use this kind of sledge to construct huge stone monuments," Harris was quoted as saying by 'The Telegraph'.
"And similar y-shaped sleighs have been found dating back to 2000 BC in Japan which we know were used to move megaliths," he added.
Stonehenge was built during the Neolithic period, between 4,000 and 5,000 years ago. The very large standing stones at the megalithic monument, which weigh between 30 and 40 tonnes are of a local sandstone, but it is the smaller bluestones which have intrigued experts as they can only be found in Wales.