Salt

Geologist Dr Iain Stewart presents a series showing how the rocks beneath our feet have shaped human history.

He takes us on a tour of the Mediterranean to show how salt is central to its history, playing a crucial role in everything from the existence of ice ages to the preservation of food and dead bodies in ancient Egypt.

His whistle-stop tour takes in many tourist destinations in Egypt, Venice and Sicily, but he provides a unique geologist's insight which can't be found in the guide books.