The Mystic Lakes are a pair of beautiful lakes located in the towns of Arlington, Winchester, and Medford, and are part of the Mystic River watershed. The Upper Mystic Lake is fed by the Aberjona River, while the Lower Mystic Lake drains into the Mystic River, which eventually flows into the Boston Harbor. The lakes are popular for swimming, sailing, fishing, and other recreational activities. The eastern shore of the lakes is also home to the Mystic River Reservation, a park that offers scenic views and trails for walking and biking. 

Shoreline access is excellent along the eastern and southern shores, and there are smaller accessible sections scattered elsewhere around the pond. Boat access is provided by a paved launching ramp (presently in poor condition but suitable for small boats) located off the Mystic Valley Parkway near the lake’s outlet.

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.

Mystic River State Reservation is open year-round, from dawn to dusk. The banks of the Mystic River are almost entirely publicly owned, from the Amelia Earhart Dam at the mouth of the Mystic Lakes, making it one of the Commonwealth’s best-protected streams. The river has been much altered since the 1800s when its shores were largely salt marsh.