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 .
Thiên Đường Cave
Thiên Đường Cave (Paradise Cave) is a cave in Phong Nha-Kẻ Bàng National Park, UNESCO's World Heritage Site, 60 km northwest of Đồng Hới city.
Thiên Đường Cave is located on an elevation of 200 meters above the sea level, near the west branch of Ho Chi Minh Highway, in Son Trach Commune, Bố Trạch District, Quảng Bình Province, Vietnam. The cave was discovered by a local man in 2005 and the first 5 km of this cave was explored by explorers from British Cave Research Association in 2005, the whole 31 km was explored and publicly announced by the British cave explorers. This cave is 31 km long, longer than Phong Nha Cave which had been considered the longest cave in this national park. The height can reach to 72 m and 150 m wide. The limestone formation is also more spectacular than that of Phong Nha Cave. The British cave explorers were impressed by the beautiful and spectacular stalactites and stalagmites inside this cave and they named it "Thiên Đường Cave" ("Paradise Cave").
In 2012, a new species of troglobiontic scorpion species, "Vietbocap thienduongensis" was found in here.