Glen Roy (Scottish Gaelic: Gleann Ruaidh, meaning "red glen") in the Lochaber area of the Highlands of Scotland is a glen noted for the geological phenomenon of three loch terraces known as the Parallel Roads of Glen Roy. The terraces formed along the shorelines of an ancient ice-dammed loch that existed during a brief period (some 900–1,100 years in duration) of climatic deterioration, during a much longer period of deglaciation, subsequent to the last main ice age (the Devensian). From a distance they resemble man-made roads running along the side of the glen, hence the name. Much of the glen is designated as a national nature reserve.