Billed as the world's toughest 5K, the Mount Marathon race in Seward, Alaska sees competitors make a gruelling 1,000 metre ascent up cliffs and scree before plunging back down to the finish line.
Mount Marathon
Billed as the world's toughest 5K, the Mount Marathon race in Seward, Alaska sees competitors make a gruelling 1,000 metre ascent up cliffs and scree before plunging back down to the finish line.
