'Krubera cave' (see the pic) is the Deepest cave known on Earth . This cave is also called as 'Voronya cave' and is located in the Abkhazia. Its deepest explored point is '2.191 kilometers' in depth which is calculated as the distance between the altitude entrance of the cave and its bottom.
It was discovered and recorded by the 'Ukrainian Speleological Association' when they carried out an expedition to measure the deepest point of the cave in 2004. They have set another record for reaching a depth greater than 2000 meters for the first time in the history of Speleology.
Also read : Deepest Borehole in the World
Credits : Julie Richman
Till today, Krubera cave remains the only known cave on earth deeper than 2000 meters. During the "Journey towards The Center of the Earth', Irish explorers have installed data logging devices to measure the surface conditions and other parameters to preserve the records.