The Bay Circuit forms a rough C-shaped arc between and north, west, and south of Boston. Although much of the trail follows a single route, several sections split in two and rejoin. The northern terminus of the trail is also divided: its northernmost section ends at Plum Island in Newburyport, and a southerly branch extends to the sea in the town of
Ipswich. The Bay Circuit passes through
Plymouth County,
Norfolk County,
Middlesex County, eastern
Worcester County,
Bristol County and
Essex County, Massachusetts.
Southern third The southern third of the Bay Circuit begins at Kingston Bay, a part of
Plymouth Bay, as a loop between
Duxbury,
Kingston, and
Pembroke, then continues as primarily one route through
Hanson,
East Bridgewater,
Bridgewater,
West Bridgewater,
Easton, and
Sharon. Features along this route include Bay Farm (Massachusetts DCR), cranberry bogs,
Silver Lake Sanctuary, the Central Greenbelt, Willow Brook Farm Preserve, Hanson Town Forest,
Hockomock Swamp, Little Cedar Swamp,
Bridgewater Iron Works Park,
Lake Nippenicket, the
Reverend James Keith Parsonage,
West Bridgewater State Forest, Satucket River Conservation Area,
Sachem Rock Farm,
Borderland State Park,
Moose Hill Wildlife Sanctuary, Hill Top Farm, Adams Farm, Great Cedar Swamp, The Pinnacle, and the Old Indian Trail.
Middle third The middle third of the Bay Circuit passes through the towns of
Walpole,
Medfield,
Sherborn,
Ashland,
Framingham,
Southborough,
Sudbury,
Wayland,
Lincoln, and
Concord. Features along this route include
Noon Hill,
Medfield Rhododendrons, the
Charles River,
Rocky Woods,
Fork Factory Brook, Little Farm Pond,
Broadmoor Wildlife Sanctuary, Sherborn Town Forest,
Rocky Narrows, Ashland Town Forest,
Sudbury Reservoir,
Callahan State Park,
Nobscot Conservation Land, Turenne Wildlife Habitat,
Garden in the Woods, Devil's Den, Heard Farm,
Great Meadows National Wildlife Refuge, the
Mass Central Rail Trail—Wayside,
Mount Misery (Lincoln, Massachusetts), Round Hill, and Haynes Meadow. Smaller networks of interconnecting side trails are prevalent throughout.
Northern third North of Concord, the Bay Circuit splits into two tracks. The eastern track passes through the towns of
Bedford,
Billerica, and
Tewksbury while the western track passes through
Acton,
Carlisle,
Westford,
Chelmsford,
Lowell, and
Tewksbury. The two branches converge in
Andover and continue through
North Andover,
Boxford,
Georgetown,
Rowley, and
Ipswich before splitting again into two terminal routes. The southern route continues east through
Hamilton to end at the
Atlantic Ocean in east Ipswich while the northern route passes northeast through east Rowley,
Newbury, and
Newburyport ending at the Atlantic Ocean at Plum Island. Features along this route include the
Walden Pond State Reservation, Adams Woods, the
DeCordova Museum, the Dana Museum, Flint's Pond conservation areas,
Drumlin Farm, the
Bruce Freeman Rail Trail,
Minuteman National Historical Park, the
Assabet River, Fawn Lake, Nashoba Brook, the
Sudbury River,
Lowell National Historic Park, the
Merrimack River, Kerouac Park,
Lowell Heritage State Park,
Carlisle Pines State Park,
Middlesex Canal, Wilderness Park, the
Concord River, the
Minuteman Bikeway, Indian Springs, Deer Jump Reservation, Harold Rafton Reservation, Haggetts Pond, Indian Ridge Reservation,
Harold Parker State Forest,
Ward Reservation,
Boxford State Forest, Bald Hill Reservation, Phillips Wildlife Sanctuary, Pomp's Pond,
Georgetown-Rowley State Forest,
Cleaveland Farms State Forest,
Willowdale State Forest,
Bradley Palmer State Park,
Appleton Farms, Prospect Hill, the
Ipswich River, Castle Neck River,
Castle Hill, Castle Neck, the Ipswich Lighthouse, William Forward Wildlife Management Area,
Parker River National Wildlife Refuge,
Old Town Hill,
Joppa Flats Education Center, and
Plum Island. ==References==