Gasherbrum IV is a mountain in the Karakoram range, in China and Pakistan. It is also known as K3. It is the 17th highest mountain in the world. A well known feature is the west face, which is called the "Shining Wall". Gasherbrum IV is considered as one of the most difficult mountains to climb. The first people to reach the top were Walter Bonatti and Carlo Mauri, in 1958.