Challenger Deep is the deepest known point in Earth’s oceans, located in the Mariana Trench.
It lies in the western Pacific Ocean, east of the Mariana Islands. Modern measurements place its greatest depth at roughly 10,900 metres, although the exact figure varies with survey method, equipment, and the reference level used for the sea surface.
The first crewed descent took place in 1960, when Jacques Piccard and Don Walsh reached the deep in the bathyscaphe Trieste. Film director and explorer James Cameron made a solo descent in 2012 in the submersible Deepsea Challenger.
Challenger Deep is part of a subduction zone, where the Pacific Plate is forced beneath the Philippine Sea Plate. The immense pressure, darkness, cold, and limited food supply make the environment difficult to explore, but specialized organisms have been detected there.