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 .
Tham Phra Wang Daeng
Tham Phra Wang Daeng, also known as the Cave of the Monk (), is a deep cave located in Thung Salaeng Luang National Park, Amphoe Noen Maprang, Phitsanulok Province, upper central Thailand. It is the longest cave in Thailand, the distance is about 13 kilometers. Buddhist statues and relics, carvings and reliefs, a subterranean river, multiple bat colonies, and a trove of speleothems populate the cave. In 2003, a biological expedition to the cave resulted in the discovery of new fish species, including discoveries in the Balitoridae and Cyprinidae families.