The Orange Loop Trail at the Fork Factory Brook Reservation in Medfield, Massachusetts is an easy, low-trafficked, 1.5 mile hike down to an old mill site and through deciduous and coniferous forests outside of Boston. The old mill site is located behind the pond, which is located at the southern portion of this trail's GPS data along Mill Brook. At the back of the pond there's an old stone dam, but there's not much to see now other than a small dam with a drainage runoff which feeds Mill Brook south of this area.
Beware that flooding from recent rainfall may cause the trail to be cut off in certain places.
For an additional interesting hike in the area, be sure to check out the trails at the Rocky Woods Reservation across the street.