How many people does it take to build Stonehenge?

The building of Stonehenge has been a topic of discussion for centuries but today all our questions may be answered.

A group of volunteers in London is conducting a mass experiment to find out how the ancient monument came to be.

At noon today, 23 May, the team will attempt to drag a one tonne concrete block using a replica of a neolithic wooden sledge. Each of the famous bluestones at the site in Wiltshire weighs at least double that but it will help researchers understand the origins of the World Heritage Site.

A demonstration of the combination of ropes and logs that might have been used to move the stones Credit: UCL

The sight and sounds of hordes of volunteers attempting to drag the sledge around Gordon Square Park in the capital, using brute strength and ancient technology should be quite impressive. Especially when you consider that the building of Stonehenge has been estimated at taking the equivalent of 10 million combined hours of labour.

The researchers think it will take between 40 and 50 people to shift the concrete block.

The bluestones weigh at least two tonnes - the volunteers will be working with a one tonne concrete block Credit: PA

Some believe that aliens were responsible for the construction of the monument. It is hoped seeing the concrete block moved by people power will dispel that and other myths surrounding Stonehenge and other sites.