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.
Yarlung Tsangpo Grand Canyon
The Yarlung Tsangpo Grand Canyon or Yarlung Zangbo Grand Canyon () or simply the Tsangpo Canyon, Brahmaputra Canyon or Tsangpo Gorge, along the Yarlung Tsangpo River in Tibet Autonomous Region, China, is the deepest canyon in the world, and at 504.6 km (314 miles) is slightly longer than the Grand Canyon in the United States, making it one of the world's largest. The Yarlung Tsangpo (Tibetan name for the upper course of the Brahmaputra) originates near Mount Kailash and runs east for about 1700 km, draining a northern section of the Himalayas before it enters the gorge just downstream of Pei, Tibet near the settlement of Zhibe. The canyon has a length of about 240 km (150 miles) as the gorge bends around Mount Namcha Barwa (7782 m) and cuts its way through the eastern Himalayan range. Its waters drop from about 2,900 m near Pei to about 1,500 m at the end of the Upper Gorge where the Po Tsangpo River enters. The river continues through the Lower Gorge to the Indian border at an elevation of 660 m. The river then enters Arunachal Pradesh and eventually becomes the Brahmaputra.