Britain's Secret Treasures

The countdown of the 50 greatest treasures found by the British public continues from 18 to 11. Jon Culshaw goes on the trail of some Viking treasure which gives a clue to the origins of the north/south divide, Dan Lobb reveals how a Bronze Age stash proves that the import and export business was thriving 3,500 years ago and, in Nottinghamshire, Anita Rani tells the story of a medieval chess piece - a 12th century metal knight. Presented by Michael Buerk and Bettany Hughes.