You know Sir Edmund Hillary and Tenzing Norgay, right? Of course... the first to summit Mt. Everest, the tallest mountain in the world. May 1953. Fourteen months later, these two reached the top of K2 (the highest summit of the Karakoram Range). K2 is the second-highest mountain in the world, only 247 meters shorter than Mt. Everest. Besides that, K2 is widely considered a far more difficult climb than Everest.