At 36,201 feet deep, the Mariana Trench is the deepest location on earth. Found in the Pacific Ocean, just east of the 14 Mariana Islands, the trench was first explored in 1960 by Swiss scientist Jacques Piccard and US Navy Lt. Donald Walsh in bathyscaph “Trieste”, a submersible manned vessel. The Swiss-designed, Italian-built, United States Navy bathyscaphe Trieste reached the bottom at 1:06 p.m. on January 23, 1960, with U.S. Navy Lieutenant Don Walsh and Jacques Piccard on board. Only three descents have ever been achieved. The first was the manned descent by Trieste in 1960. This was followed by the unmanned ROVs Kaikō in 1995 and Nereus in 2009. These three expeditions directly measured very similar depths of 10,902 to 10,916 m. More at Wikipedia.