Bathyscaphe Trieste
On 23 January 1960, she reached the ocean floor in the Challenger Deep (the deepest southern part of the Mariana Trench), carrying Jacques Piccard and Don Walsh. This was the first time a vessel, manned or unmanned, had reached the deepest known point of the Earth's oceans. The onboard systems indicated a depth of , although this was revised later to ; fairly recently, more accurate measurements have found Challenger Deep to be between and deep.
List of deepest mines
This list of deepest mines includes operational and non-operational mines that are at least , which is the depth of Veryovkina Cave, the deepest known natural cave in the world. The depth measurements in this list represent the difference in elevation from the entrance of the mine to the deepest excavated point.