Chevé Cave
Chevé Cave ( ; ) is a deep cave located in the Sierra Juárez mountain range in the southern Mexico state of Oaxaca. As of 2003, its deepest point has been measured at deep, making it the second deepest known cavern in the Western Hemisphere and the world’s 12th deepest cave. The cave's deepest known point is nearly one vertical mile and seven horizontal miles from the entrance, ending in a terminal sump. The present limit of exploration in Chevé, at 9.3 kilometers from the nearest entrance, represents one of the most remote locations ever attained inside any cave on Earth. The logistics of reaching this point are enormous: more than two kilometers of rope need to be rigged and three underground camps established. Chevé is the deepest proven freshwater hydrological system in the world. Temperatures in Chevé are moderate, ranging from . It has been most thoroughly explored under the leadership of caver Bill Stone.
Tears of the Turtle Cave
The entrance to Tears of the Turtle Cave was found in 2006. The cave passage is mostly a two to three foot wide fissure that follows a stream downward through numerous rappels. In 2014 a team of nine cavers explored new passage pushing the cave to a depth of 1629 feet and in doing so passed New Mexico's Lechuguilla Cave to become the deepest known limestone cave in the United States. Exploration continued in 2016 when teams returned to push the cave to its current known depth of 1659 feet. On those trips the difficulty necessitated establishing camp in the cave for the first time. This, along with the technical rope work, 39 degree temperature, and remote location of the cave make continued exploration difficult. A return trip is currently planned for 2019.