largest underwater trench
Location of the Mariana Trench. The Mariana Trench or Marianas Trench is the deepest part of the world's oceans. It is located in the western Pacific Ocean, an average of 124 miles/200km to the east of the Mariana Islands, in the Western Pacific East of Philippines. The trench is about 2,550 kilometres (1,580 mi) long with an average width of 69 kilometres (43 mi).