The deepest part of the ocean is the Challenger Deep in the Mariana Trench, which is located in the western Pacific Ocean. The Mariana Trench is east of the Mariana Islands and near Guam.
The Challenger Deep is the lowest point known on Earth. The depth of the Challenger Deep is estimated to be about 36,070 feet (10,994 meters) based on the latest measurements as of my knowledge cutoff in 2021. It’s named after the HMS Challenger, whose crew first sounded the depths of the trench in 1875. Only a few expeditions have descended to the bottom of the Challenger Deep due to the extreme conditions found there, including immense pressure, low temperatures, and complete darkness.