In the Finger Lakes region of New York State, the southern ends of Seneca Lake and Cayuga Lake in particular are etched with glens, although in this region the term "glen" refers most frequently to a narrow gorge, as opposed to a wider valley or strath. 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 rocky glens (e.g., Watkins Glen, Fillmore Glen State Park and Treman State Parks) and waterfalls (e.g., Taughannock Falls) as rainwater has flowed down toward the lakes below.