North Reservoir in Middlesex Fells Reservation is one of three reservoirs in the area, used as a source of drinking water. While access to swimming in the reservoirs is restricted, visitors can enjoy hiking, biking, and horseback riding along the 5.2-mile Reservoir Trail, which is marked by orange blazes.
Most of the trails directly along the shore of the reservoirs are prohibited, but here you get really close to the North Reservoir with a nice view over the water.