In this final episode, Will completes his tour around Wales in the south of the country. From the resting place of early man to a lost mediaeval city, and from a forgotten prisoner of war camp to an abandoned coke works, Will uncovers historical gems that reveal parts of south Wales you never knew existed.

Will explores the subterranean wonders of Wales and discovers some remarkable stories, from a smuggler's den to an ancient bone cave.

Will Millard discovers the forgotten history of Wales's copper story by exploring some extraordinary locations that reveal how this country once led the world in copper production.