A col is the lowest point on the saddle between two mountains. Graham Robb has spent years uncovering and cataloguing the 2002 cols and 105 passes scattered across the British Isles. Some of these obscure and magical sites are virgin cols that have never been crossed. Dozens were lost by the Ordnance Survey and are recorded only in ballads or monastic charters. The 11 cols of Hadrian's Wall are practically unknown and have never been properly identified. These under-appreciated slices of natural beauty provide a new way of looking at British history, and a challenge for cyclists and walkers.