Aerial cameras track the Ffestiniog Railway as it carves a path through of Eryri changing Welsh history, from Porthmadog to the slate mines of Blaenau Ffestiniog

Hugh Bonneville narrates a journey through the rolling hills of England's south-west on the West Somerset Railway created by Isambard Kingdom Brunel. Widely recognised as one of the greatest engineers of all time, Brunel's remarkable railways and structures are known worldwide. This episode travels along his railway through the Quantock Hills to the Bristol Channel.