Starting at the Coastal Path plinth in St Dogmaels, you head in the opposite direction of the coastal path and follow the following route.
The route is roughly 36 miles and has 5,000ft of climbing in it.
To complete the challenge you must stick exactly to this route, no variation is allowed. It can be attempted in either direction.
The current fastest known time is 8 hours, 55 minutes.
Please email us if you have completed the route and we'll add you to the list.