K2, also known as Mount Godwin Austen, is part of the Himalayas. The icy peak sits on the border of Pakistan and China. Towering at 28,238 feet, it is the world's second-highest mountain after Mount Everest. K2 is considered one of the hardest peaks to climb. Many brave mountaineers turn back before they reach the summit. (AMAIA AROZENA & GOTZON IRAOLA—GETTY IMAGES)