Britain's first national trail, the Pennine Way, celebrates its 50th anniversary on 24 April 2015.
The long-distance walking route stretches 268 miles from Edale in Derbyshire through the Yorkshire Dales to Teesdale, the North Pennines and the Scottish Borders.
More than 80 years ago, Kinder Scout was a place of revolution as people demanded access to the countryside. Protests resulted in a fracas on the fellside, a key moment in the battle for the "right to roam" for ramblers.
It was against this background that the idea of a long-distance trail in the North of England started to take shape.
Presenter Paul Rose takes a journey along the "backbone of England". He meets Sylvia Franks, friend of campaigning hill walker Tom Stephenson, the architect of the route as we know it today.