Echo Bridge, Hemlock Gorge This is an easy walkfeaturing a 1-mile walk in Hemlock Gorgeora 3-mile walk that includes Hemlock Gorge and Newton Upper Falls. The scenic arch of Echo Bridge, completed in 1877, connects the two banks of the Charles River over Hemlock Gorge, offeringgreat views of the Charles River and the associated valley. The area featureswell-marked trails with small platforms situated beneath the largest arch of the bridge, wherevisitors can experience an impressive echo that returns up to 15 reverberations of the human voice. The view upstream from the bridge includes the site of Newton’s first mill on the Charles River, built in 1588, and acoustic experiments are available on the listening platform.