BBC News By Chris Wood image copyrightSteven Tasker image captionHow Steven believes the machine could have looked - with the stone held over a circular board in the middle and wooden planks pulled sideways to propel the feet forward It is a mystery that has confounded experts for centuries - how were huge stones transported 180 miles (290km) from the Preseli Hills to Stonehenge? However, a Denbighshire man believes it was a long-forgotten "machine" which appeared to defy gravity and was even possibly referenced in the Bible. A leading expert said his theory was "as good as any, and better than most".