Geologist Dr Iain Stewart presents a series showing how the rocks beneath our feet have shaped the human history of the Mediterranean. His whistle-stop tour takes in familiar tourist destinations in Greece,Italy and Portugal, but provides a unique geologist's insight which can't be found in the guidebooks.Rocks played a crucial role in determining the beliefs of ancient civilisations, but they are also a major influence on how we understand our planet today. From the spread of Christianity to recent discoveries about the extinction of dinosaurs, geology has played a vital role.