Which ocean contains the Mariana Trench, the deepest known place on Earth?

The Mariana Trench, the deepest known place on Earth, lies in the Pacific Ocean.

The trench is an arc-shaped depression in the western Pacific east of the Mariana Islands. It formed where the Pacific Plate is being forced beneath the Philippine Sea Plate, a process called subduction. The trench extends for roughly 2,550 kilometers.

Its deepest surveyed area is the Challenger Deep, which reaches nearly 11,000 meters below sea level. Exact measurements vary slightly by expedition and method, but the site is deeper than Mount Everest is tall. The immense pressure, darkness, and near-freezing water make the environment difficult to explore.

The Mariana Trench is sometimes confused with the Tonga Trench, which is also extremely deep, or with the deepest point of an ocean basin as a whole. Don Walsh and Jacques Piccard first reached the Challenger Deep in 1960; James Cameron made a solo descent in 2012.