This ride is named after the shared use path that the ride starts on. The two tunnels cycle path is just south of Bath and runs along the disused Somerset and Dorset Joint Railway. The name comes from the Combe down and Devonshire tunnels that make up a significant proportion of the cycle path.
The ride isn't all about cycle paths, there's some cracking off-road sections, some of which are shared with the Englishcombe ride. The majority of the climbing is on roads, leaving some cracking off road descents.