"Modern explorer Nicholas Crane travels across eight maps that changed the face of Britain in a series of geographical challenges through some of today's wildest landscapes, telling the story of British mapmaking from the time of Chaucer through to the current generation of cyber-mappers. Here, he travels across William Roy's pioneering military map of 18th-century Scotland, and uses it to lead him through some wild Highland landscapes.

After the Battle of Culloden in 1746, the British Army decided it desperately needed an accurate map if it was to govern the rebellious Scottish Highlands. They gave a young military engineer, William Roy, the job. With the help of army volunteers, Nick Crane tests out the accuracy of Roy's methods ~ using 18th-century chain traversing ~ and then follows one of Roy's mapped roads across some of the most dangerous and exposed terrain in Scotland. He ends up at Rannoch Moor, where Roy's road appears to run out, or does it?"