The two tallest mountains in the world are found in Nepal and Pakistan. The tallest mountain in the world is the Mt. Everest found in the Himalayan range. It stands at 29,035 feet above sea level. Anyone who climbs this mountain is expected to be a professional climber as the conditions in the mountain changes at fast rate. The second highest mountain in the world is K2 or Mount Godwin Austen found in the Karakoram range. It stands at 28,250 feet above sea level.