A glen is a valley, typically one that is long, deep, and often glacially U-shaped; or one with a watercourse running through such a valley. The word comes from the Irish language/Scottish Gaelic language word gleann, or glion in Manx. In Manx, glan is also to be found meaning glen. As the name of a river, it is thought to derive from the Welsh languageglan meaning clean, or gleindid meaning purity. In the Finger Lakes Region of New York State, the southern ends of Seneca and Cayuga in particular are etched with glens. The steep hills surrounding these lakes are filled with loose shale from glacial moraines. This material has eroded over the past 10,000 years to produce beautiful rocky glens (e.g., Watkins Glen and Treman State Parks) and waterfalls as rainfall has descended toward the lakes below.
