The Mariana Trench is the deepest in the world, with a maximum depth of 36,037 feet. It is located in the western Pacific Ocean between Japan and Papua New Guinea. The trench is 1,580 miles in length and 43 miles wide. Its deepest point is called the Challenger Deep. If placed within the trench, Mount Everest would still have over 1 mile of water over it. The United States designated the site as a National Monument in 2009. The HMS Challenger first explored the trench during its survey in 1875. The expedition used a weighted rope and recorded a depth of 26,850 feet. Despite the incredible depth, living creatures such as snailfish and amphipods have been seen at a depth of over 26,000 feet.