Britain's Ancient Capital: Secrets Of Orkney

Chris Packham uncovers the secrets revealed by the DNA of Orkneys unique vole, Neil Oliver explores Orkneys tombs and monuments, Dr Shini Somara experiments to discover how the Orcadians could have moved giant blocks of stone over rough ground, and archaeological adventurer Andy Torbet climbs Orkneys most challenging sea-stack to unlock the story of Orkneys unusual geology.

Andy Torbet dives below the waves in search of the inspiration for the first stone circle.