Last summer, former mountain-bike downhill world champion Gee Atherton spotted an “unscalable ridge” behind Dyfi Bike Park in Snowdonia, North Wales, a feature of the mountain Tarren y Gesail. Six feet off one side of the ridge, the land falls away for hundreds of feet but offers stunning views. Naturally, Atherton couldn’t resist the idea of riding it. In The Ridgeline, presented by Atherton Bikes and Continental tires, he brings his vision to life.