The archaeological sites of Orkney give us an unparalleled glimpse into prehistory. Inscribed as the 'Heart of Neolithic Orkney' World Heritage Site in 1999, four great monuments - the village of Skara Brae, the Ring of Brodgar, the Stones of Stenness and the burial mound of Maeshowe - are also at the centre of the archipelago's story. Caroline Wickham-Jones looks at what makes these monuments so special. She explores the Neolithic world in which they were built, how they come to be a focus through the ages, and what they mean today. Picts, saints, Vikings, antiquarians and tourists populate Orkney's past: a history which is channelled - like the sun entering Maeshowe on the winter solstice - through these 'dances of stones'.