Bottleneck (K2) Bottleneck (K2) The Bottleneck is a location along the South-East Spur, known also as Abruzzi Spur— the most used route to the summit of K2, the second-highest mountain in the world, in the Karakoram, on the border of Pakistan and China. The Bottleneck is a narrow couloir, which is overhung by seracs from the ice field east of the summit. The couloir is located only 400m below the summit, and climbers have to traverse about 100m exposed to the seracs to pass it. Due to the height (8200m) and the steepness (50-60 degrees) this stretch is the most dangerous part
Karakoram them exceeding : K2, the second highest peak in the world at , Gasherbrum I, Broad Peak and Gasherbrum II. The range is about in length, and is the most heavily glaciated part of the world outside the polar regions. The Siachen Glacier at and the Biafo Glacier at rank as the world's second and third longest glaciers outside the polar regions. The Karakoram is bounded on the east by the Aksai Chin plateau, on the northeast by the edge of the Tibetan Plateau, and on the north by the river valleys of the Yarkand and Karakash rivers beyond which