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.
Tés
The Alba Regia cave is the third deepest cave in the country. Its exploration was begun in 1975 and due to the hostile environment it took for quite a long time. In October, the entrance test hole, which depth is almost five meters, was dug. Exploratories went along the next 30 metres through strait routes full of scree. Then, beyond some crannies, they reached the so-called "Explorer branch" of the cave in which the first stalagmites could be seen. At the bottom of the test hole, sunk in extremely difficult circumstances, the channel was opened on 24 October. The air temperature of the inner passages of Cave Alba Regia is about 7 degrees lower than the Hungarian average 8,1-8,5°C. During the exploration, the strong enrichment of carbon dioxide in some passages became apparent. It is Istvan Eszterhas who collects and converses the wildlife of the cave that was wholly closed until its discovery. He started trapping in 1976, and even in that year he could differentiate between 21 species. In 1977, the number of cave creatures increased to 56, and in 1979, it was as high as 70. The cave can be visited only with a permission and a professional guide.