The Coast2Coast Winter Ultra is a 60 km winter trail ultra on the Llyn Peninsula in North Wales. It starts and finishes at the Nant Gwrtheyrn Welsh Language Centre, following The Mariners Trail. The course involves approximately 1,280 metres of climbing and descent, with a 12-hour time limit for participants.
The course is marked and features four aid stations stocked with vegan provisions. The "Bobble Brutal" marshals will be present on the course. Notable sections include the "Steps of Hell" and a final descent. Finishers receive a medal, and the event awards ITRA points, a Mountain Level 2 rating, a Finisher Level 360 rating, and a National League place.