Boybuloq Cave
Boybuloq Cave (also known as Boy Bulok) is a limestone cave in Uzbekistan and the deepest known cave in Asia. It is located high in the Gissar Range of mountains, near to Dehibolo, Uzbekistan's highest village. The cave and wider area is inaccessible for much of the year due to snow. Long-known to local people because of a nearby spring the cave was first explored by speleologists in 1984. Since then expeditions have mapped of passages in the cave and reached a total depth of . The cave could potentially extend much deeper and become the deepest in the world.
Carreg Cadno
Ogof Ffynnon Ddu, Britain's deepest cave lies under the northern slopes of Carreg Cadno. The vertical interval between the sink of the Byfre Fechan stream at Pwll Byfre and its resurgence at Ffynnon Ddu is 300m / 1000 ft. The national nature reserve has been established to protect both the surface features and the vegetation and habitats which they provide and also the extensive cave network beneath.