Until the BBC dedicated an hour long programme to it in early 2021, few knew that some stones on a peaty moorland in Pembrokeshire were once the largest stone circle in Britain, and they were the exact stones transported to create the 'original' Stonehenge. Similarly, until recently a peaty moorland site in Carmarthenshire had been designated as merely one of nearly 700 Iron Age forts in Wales. Now research has concluded that it is not only several thousand years older, but was once a major Neolithic religious centre, and, indeed, is the largest ancient stone monument in Britain. This book compellingly makes the case in a heavily researched, but lightly written, style that encourages the reader to draw their own conclusions.