Boybuloq Cave
The cave is the deepest known cave in Asia having been explored to a depth of from the entrance. At the lowest discovered level a water-filled siphon blocks further exploration. It is thought that the cave has the potential to be the deepest known cave in the world, with a theorised depth of making it deeper than the Veryovkina Cave. The explored length of the cave is .
Bill Steele (cave explorer)
Continuing to explore caves throughout the United States, Steele led and participated in expeditions to Sistema Huautla in Mexico almost every year through the 1980s. In 1987, the Huautla expedition connected the deep cave Nita Nanta to Sistema Huautla; which established it as the second deepest cave in the world. Steele went to Kijahe Xontjoa on the plateau to the east of Huautla with an expedition of Swiss explorers in 1993, and explored depths over 1,000 meters.