The Parallel Roads of Glen Roy, Scottish Highlands, represent a series of ice-dammed proglacial lake shorelines produced during the cold climate of the Younger Dryas (GS1).

It has been demonstrated by Dawson, Hampton, Harrison, Greengrass and Fretwell (2002) that each lake shoreline exhibits evidence of glacio-isostatic tilting associated with the decay of the last (Late Devensian) ice sheet.

Consideration of the ice-dammed lake shoreline data also points to the former occurrence of two separate episodes of tectonic activity during the Younger Dryas (Greenland Stadial 1 - GS1).

Charles Darwin visited the glen in June 1838 and, drawing on his recent findings in South America during the Beagle expedition concluded that the shorelines were raised beaches of marine origin.

This was contradicted in 1840 by Louis Agassiz's Glacial theory which postulated that the Glen Roy shorelines had been cut by freeze-thaw processes of loch ice during the maximum extent of glacial ice in the climatic reversal known as the Younger Dryas / Greenland Stadial, or locally the Loch Lomond Readvance.

Interest in the Parallel Roads continues to this day, both among earth scientists intrigued by the dramatic processes that shaped that landscape, and among tourists attracted by the natural wonder of the landforms.