It may not be particularly long, but you’ll be hard pressed to find a race that is more challenging and grueling than Mount Marathon, held on an annual basis in Seward, Alaska. The run started as a challenge between two friends to see who could get to the top of the 3022-foot (921-meter) Mount Marathon, which sits just outside of town. The entire run is only 3 miles, but as you’ll see in the clip below, they are some of the toughest 3 miles you’ll ever run. Going up is really hard, coming back down is another animal altogether. I had the benefit of being in Seward for this run a few years back, and it is a sight to behold.