“It’s true that we did the experiment on flat ground, and there would have been steep slopes to navigate when going through the Preseli Mountains, but actually this kind of system works well on rough terrain.

“We know that pre-industrialised societies like the Maram Naga in India still use this kind of sledge to construct huge stone monuments. And similar y-shaped sleighs have been found dating back to 2000BC in Japan which we know were used to move megaliths.

“The Chinese also used sleighs to build the Forbidden City and some of those blocks are 123 tonnes. So in comparison, these are blocks are quite small.

“Some people think they may have been pulled by oxen, but actually oxen are quite belligerent and difficult to control. This experiment shows that humans could have carried out the task fairly easily.

“We now want to go back and crunch the numbers and hopefully from the data we can work out how long it might have taken to bring the stones here.”