Glen Roy (Scottish Gaelic: Gleann Ruaidh meaning "red glen") in the Lochaber area of the Highlands of Scotland is a National Nature Reserve and is noted for the geological puzzle of the three roads ("Parallel Roads"). The "Parallel Roads" of Glen Roy are lochterraces that formed along the shorelines of an ancient ice-dammed loch. The loch 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.