Chevé Cave
Chevé Cave ( ; ) is a deep cave located in the Sierra Juárez mountain range in the southern Mexico state of Oaxaca. As of 2003, its deepest point has been measured at deep, making it the second deepest known cavern in the Western Hemisphere and the world’s 12th deepest cave. The cave's deepest known point is nearly one vertical mile and seven horizontal miles from the entrance, ending in a terminal sump. The present limit of exploration in Chevé, at 9.3 kilometers from the nearest entrance, represents one of the most remote locations ever attained inside any cave on Earth. The logistics of reaching this point are enormous: more than two kilometers of rope need to be rigged and three underground camps established. Chevé is the deepest proven freshwater hydrological system in the world. Temperatures in Chevé are moderate, ranging from . It has been most thoroughly explored under the leadership of caver Bill Stone.
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.