You will need to take the path to the left after #12 (see waypoint), this leads to the Dunchurch Bridleway and more caches.
The old railway path is called the Lias Line due to a huge number of dinosaur fossils being found in the limestone geology.
There is a free car park at Cornwallis Road.
Visit www.cawstongreenway.co.uk to see more about the railway path.