Julia Bradbury begins her exploration of Britain's lost rail empire in the heart of the Peak District, with a walk along the popular Monsal Trail. Limestone cliffs and gorges abound, not to mention the tunnels and soaring viaducts of the Midland Railway--one of the most dramatic and unlikely main lines ever built.

Julia takes a stroll through the gorgeous Mawddach estuary, a forgotten part of Snowdonia. Popular with vacationers in the 1860s who used this line to connect to English cities.

Tin and copper once made the area around Redruth the richest patch of land in the country. They also inspired great engineering feats and some pioneering tramways--the forebears of Britain's rail empire. Julia Bradbury has her work cut out as she crosses an entire country, winding past Cornwall's crumbling engine houses, following a railway that hasn't operated in 140 years.

Julia Bradbury's first walking foray into Scotland has a very distinct flavour to it: whisky! The Speyside Way is one of Scotland's great walking routes, and between the villages of Craigellachie and Ballindaloch, it follows the route of the railway that once served a remote area and a world-famous drinks industry.

Julia walks a railway line that once ran from Weymouth across to Chesil Beach and Portland. She discovers the unique history of Portland Harbor and its main export, Portland Stone.

Julia Bradbury's last railway walk is epic, in more ways than one. Not only is this the longest and arguably most dramatic walk yet, but it passes through the unruly territory of Scottish clans and Rob Roy. The Highlands were a place to be wary of…until the railway arrived, that is.