Travellers and local people alike have long been fascinated by the Parallel Roads of Lochaber. Were these striking horizontal lines on the hillsides of Glen Roy, Glen Gloy and Glen Spean formed by giants of old, as described in Gaelic myths? Are they natural or were they formed by human activity? In the 19th century, the Parallel Roads attracted the attention of many of the founding fathers of modern geology, including the Reverend William Buckland, James Geikie, Charles Darwin, Charles Lyell and Joseph Prestwich. This interest ensured that the Parallel Roads, and Glen Roy in particular, featured prominently in the development of geological science.

Interest in the Parallel Roads continues to this day, both among earth scientists intrigued by the dramatic geological and geomorphological processes that shaped the landscape, and among modern travellers and tourists attracted by the natural wonder of the landforms. This booklet traces the story of the formation of the Parallel Roads - a remarkable story of ice-age glaciers, vast lakes and catastrophic floods.