Kef Toghobeit Cave
Kef Toghobeit is a karst cave near the settlement of Bab Taza in Chefchaouen Province, Tanger-Tetouan-Al Hoceima, in northern Morocco. Currently known to be long and deep, it is the deepest cave in Morocco, and the third deepest cave in Africa.
Although Kef Toghobeit has been well-explored, its full extent is not yet known. Indeed, the karst topography of the Rif mountain range where the cave begins has barely been mapped - just 1000 caves are known in Morocco, and the geology would suggest that more than this exist.
Phong Nha-Kẻ Bàng National Park
Sơn Đoòng Cave (in Vietnamese: Hang Sơn Đoòng, meaning Mountain River Cave) is a relatively recently discovered cave in the national park. Found by a local man and explored and publicly announced by the British cave scientists of the British Cave Research Association, it is regarded as the largest cave in the world. The biggest chamber of Sơn Đoòng is over five kilometers in length, 200 meters high and 150 meters wide. With these tremendous dimensions, Sơn Đoòng overtakes Deer Cave of Malaysia to take the title of world's largest cave. Because the fast flowing underground river in the cave deterred the explorers from going farther, they were only able to estimate the length of the cave using a flashlight.