The deepest part of all the world 's oceans is a place called the Challenger Deep , which is in the Mariana Trench . It is 10,924 m ( 35,838 ft ) under the sea . The solid surface location on the planet closest to the center of the orb is the Challenger Deep , located in the Mariana Trench at a depth of 10,924 m ( 35,838 ft ) under the sea .