The largest "sarsen" sandstone blocks that make up the main ring of Stonehenge weigh up to 32 tons, and were probably transported from an ancient quarry located about 20 miles (32 kilometers) to the north.
But the many smaller dolerite "bluestones," which weigh up to 2 tons and are used to mark ceremonial circles and points around the sarsen stones, were transported around 150 miles (240 km) from western Wales. [Read full story about how Stonehenge was built]
According to the legend, Stonehenge was magically moved to England and rebuilt at the direction of the wizard Merlin, as a monument for British knights killed in the wars against the invading Saxons.
This image shows Merlin wearing a purple hat, standing between two giants at Stonehenge. One giant holds a sarsen stone upright while the other places a lintel stone across the top.
The students were testing the use of a wishbone- or Y-shaped wooden sled to haul the stone block over a trackway of sawn logs, a technology known in prehistoric times and still used in some parts of the world today.
The experiment took place in London's Gordon Square, near UCL's Institute of Archaeology.
Harris told Live Science that the experiment showed it was easier to move the block than he had originally calculated. Just 10 people were needed to move the 1-ton block at a rate of 10 feet (3 meters) in five seconds, equivalent to a speed of around 1 mile per hour (1.6 km/h) of continuous hauling.
Based on the results of the experiment, Harris estimates a team of 20 people would have been able to transport one of the bluestones overland to Stonehenge using a wooden sled.
By land or water?
The researchers also considered two proposed routes that the stones may have taken: by land or a "coastal route" using wooden rafts to float the stones.
Based on the latest finds, the researchers thought it more likely that the overland route was used.
There are around 43 bluestones at Stonehenge today, but more were originally transported to the site to build the stone circle and other Neolithic ceremonial sites nearby. Many were removed in later centuries, mainly for use as building materials.
An estimate by an archaeologist in 1951 suggested 30 million hours of human labor were needed to build Stonehenge. Harris said his research indicates less labor would likely have been needed to build Stonehenge, but that was only part of the effort needed to build hundreds of Neolithic ceremonial sites across England.