In this third episode, Dan and Conrad conclude their epic expedition around the Isles of Scilly. Travelling on board Conrad’s historic boat ‘Bounty’s End’, they explore the impressive defences that line the islands’ coastlines that made them almost impregnable - guarding the Atlantic approaches.

For hundreds of years, military planners have recognised the strategic importance of the Isles of Scilly. The island’s position at the crossroads of several important sea routes made them a vital asset for Britain.

There aren’t many places in the British Isles where you can see the evolution of coastal defences from medieval to modern in such a concentrated area. Join Dan Snow and Conrad Humphreys for the final leg of their historic voyage.