Starting at Sowerby bridge, following the whole of the Rochdale canal to central Manchester.

Rochdale Canal Walking and Cycle Route (gps-routes.co.uk)

The Carrollton Greenbelt is a 16 mile paved shared-use path designed for pedestrians and cyclists. The trail runs around the perimeter of the city of Carrollton and connects neighborhoods with city parks, shopping and the University of West Georgia. This is the longest closed-loop trail in the state of Georgia.

http://www.carrolltongreenbelt.com

Although this description is written starting at Natural Bridge, this effort can be done starting and finishing at Natural Bridge or Corner Ridge.