The Parallel Roads - Lake Shorelines
The Parallel Roads represent the shorelines of the ice-dammed lakes. Typically they are narrow benches (several metres wide) cut into the bedrock of the hillsides and in places covered by remnants of lake beach gravel. They extend along much of Glen Roy and Glen Gloy and parts of Glen Spean. Probably they formed through a combination of intense frost weathering and wave action along the lake shore zone. The control of lake levels by the different cols allowed the lakes to persist for sufficiently long periods such that even the hard, Precambrian bedrock was broken up and eroded.