Mass Central Rail Trail. Waltham MA

After leaving off in Belmont, the Central Massachusetts Railroad remnant picks up at Beaver Street in Waltham where Beaver Brook threads through it at several points.

If the Somerville and Cambridge segments are showcases for state of the art linear park sections, the Waltham portions are more mysterious.

Charles River Link Trail Medfield MA.

The southern end of the Charles River Link Trail meets the Bay Circuit Trail after passing through wilds around the grounds of the decommissioned Medfield State Hospital now gradually becoming part of Medfield State Forest.

The trailhead on the eastern side is in Dover just to the north of the Dover-Sherborn Regional High School.

Bay Circuit Trail: Callahan State Park.

Callahan State Park is like Borderlands in that it occupies two towns, Framingham and Marlborough.

The Bay Circuit Trail meets it coming in from the north after passing through the Sudbury Valley Trustees parcel called the Welch Reservation.