What is the Tallest Mountain in the World?

When it comes to the tallest mountain in the world, most people immediately think of Mount Everest. Located in the Himalayas, on the border between Nepal and China, Mount Everest is the tallest mountain above sea level, standing at a towering 29,032 feet (8,849 meters). However, if we consider the tallest mountain base to summit, then Mauna Kea in Hawaii takes the crown, with its base on the ocean floor and reaching a height of about 33,500 feet (10,210 meters). So, whether your definition includes above sea level or base to summit height, these two mountains certainly stand out in the world of geography.