The Nashua River Rail Trail is a beautiful and peaceful rural trail extending through the Massachusetts communities of Ayer, Groton, Pepperell and Dunstable. The trail continues into New Hampshire just south of the town of Nashua. In autumn it provides a spectacular platform for viewing the colorful changing leaves. Along the 7 miles between Groton Center and Dunstable, a 5-foot-wide gravel equestrian path parallels the trail.