Audio clip: Adobe Flash Player (version 9 or above) is required to play this audio clip. Download the latest version here. You also need to have JavaScript enabled in your browser.

Download MP3
Today’s answer is the Preseli Hills/Mountains in West Wales, that archaeologists say are the source of massive stones used to build a recently discovered circle of stones dubbed Blue Stonehenge. Anchor Marco Werman finds out more from Professor Julian Thomas, co-director of the Stonehenge Riverside Project.