The Mystic River Reservation runs through Arlington, Medford, and Winchester and is a Department of Conservation and Recreation property. Mystic Lakes, both Upper and Lower, connect to the Mystic River; visitors can enjoy various parks and outdoor activities along the shores.

Tennis courts, playgrounds, grassy areas, boat landings, bike paths, soccer fields, and picnic tables make this a family-friendly place to visit. In Winchester, Shannon Beach, formerly named Sandy Beach, located at the northern end of Upper Mystic Lake, is popular for swimming and does indeed have a sandy beach. Kids can visit the playground here or ride bikes along the paved paths. Only nonpowered boats are allowed at the Upper Lake, but motorized boats with no wake are OK at the Lower Mystic Lake.

Remember: You can’t always swim at the beach due to water-quality issues; call ahead to check. Keep your dog on a leash and clean up after it.

The Middlesex Fells Reservation (Trip 31), in Stoneham, is about 5 miles away and has an extensive trail system.

At MA 60 near the traffic circle and before you turn onto Mystic Valley Parkway, you’ll spot a couple of places to eat.