North Dorset Trailway, between Sturminster Newton and Spetisbury. About 14 miles. The Trailway is largely made up of sections of the old Somerset and Dorset Railway which linked Bristol and Bournemouth until the 1960s. The North Dorset Trailway Network aims to extend the trail, so the route may change.
Currently the Trailway stops at Surminster Newton / Spetisbury. I'll explore the section further North, but as far as I'm aware the extension is still currently a proposal.
This will make a fun one way or out & back challenge for us locals!