Instruct: Given a question, retrieve relevant passages that can help answer the question.
Query: What is the deepest valley in the world?
The Kali Gandaki Gorge or Andha Galchi is the gorge of the Kali Gandaki (or Gandaki River) in the Himalayas in Nepal. The Kali Gandaki gorge is the deepest gorge in the world, being 24,071ft or 7,337m lower than Annapurna I which bounds it at one point.
The river region is characterised by fertile mountain valleys and includes the Yarlung Tsangpo River (the upper courses of the Brahmaputra) and its major tributary, the Nyang River, the Salween, the Yangtze, the Mekong, and the Yellow River. The Yarlung Tsangpo Canyon, formed by a horseshoe bend in the river where it flows around Namcha Barwa, is the deepest, and possibly longest canyon in the world. Among the mountains there are many narrow valleys. The valleys of Lhasa, Xigazê, Gyantse and the Brahmaputra are free from permafrost, covered with good soil and groves of trees, well irrigated, and richly cultivated.
The lakes form a peculiar landscape, not found anywhere else on the island and reminiscent of the rift valleys of central Sweden with steep cliffs and deep lakes. The other lakes on Gotland are very shallow, bowl-shaped depressions in the bedrock, filled with water. For example, Lake Bästeträsk is no more than at its deepest and Lake Tingstäde no more than . In relation to this the Lojsta Lakes are deep, more than with "Rammträsk" as the deepest at , making it the second deepest lake on Gotland. The deepest lake is "Sigvalde träsk" at . Lake Sigvalde is situated some kilometers east of the Lojsta Lakes, and is part of the same rift valley as them.
The Rift Valley lakes are a group of lakes in the East African Rift that runs north-south through the eastern side of the African continent, from Ethiopia in the north to Malawi in the south. These lakes include some of the oldest, largest, and deepest lakes in the world. Many are freshwater ecoregions of great biodiversity, while others are alkaline "soda lakes" supporting highly specialised organisms.
The Groesfaen Colliery, which at was the deepest in the Darran Valley, opened around 1902. It was nationalised in 1947 and closed in 1968.
This list of deepest mines includes operational and non-operational mines that are at least , which is the depth of Veryovkina Cave, the deepest known natural cave in the world. The depth measurements in this list represent the difference in elevation from the entrance of the mine to the deepest excavated point.
The "river region" is characterized by fertile mountain valleys and includes the Yarlung Tsangpo River (the upper courses of the Brahmaputra) and its major tributary, the Nyang River, the Salween, the Yangtze, the Mekong, and the Yellow River. The Yarlung Tsangpo Canyon, formed by a horseshoe bend in the river where it flows around Namcha Barwa, is the deepest, and possibly longest canyon in the world. Among the mountains there are many narrow valleys. The valleys of Lhasa, Shigatse, Gyantse and the Brahmaputra are free from permafrost, covered with good soil and groves of trees, well irrigated, and richly cultivated.
The extreme difference in elevation between the river valleys and the hilly plateaus of Chongqing pose a unique challenge in designing alignments for conventional rail transit lines. The network currently has the world's highest metro-only bridge, the Caijia Rail Transit Bridge for Line 6, spanning the Jialing River valley, with the bridge deck being approximately 100 m above the water. Hongtudi station is the deepest subway station in China and the second-deepest station in the world, after the Kiev Metro's Arsenalna, with Line 10's platforms being more than 94 m below the surface. Liyuchi station, also on Line 10, is the second-deepest station in China, being 76 m below the surface.
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.
The Sea of Galilee Basin or Kinneret Basin is a pull apart formed between Jordan valley fault along its eastern edge and a set of smaller faults to the north. The central site of the basin's deepest sedimentary fill (its "depocentre" in geologists' jargon) lies on the eastern side, against the continuation of the Jordan valley fault. The thickness of the fill is estimated as 3 km down to the deepest mapped seismic reflection, correlated with the top of a basalt layer that was extruded about four million years ago.
Hellhole is a large and deep pit cave in Germany Valley, eastern West Virginia. It is the 7th longest cave in the United States and is home to almost half of the world's population of Virginia big-eared bats. At 518 feet (158 meters), Hellhole is the deepest of several caves in the Valley.
The lake is deep at its deepest point, which makes it the deepest lake in the United States, the second-deepest in North America and the ninth-deepest in the world. Crater Lake is often referred to as the seventh-deepest lake in the world, but this former listing excludes the approximately depth of subglacial Lake Vostok in Antarctica, which resides under nearly of ice, and the recent report of a maximum depth for Lake O'Higgins/San Martin, located on the border of Chile and Argentina. However, when comparing its average depth of to the average depth of other deep lakes, Crater Lake becomes the deepest in the Western Hemisphere and the third-deepest in the world. The impressive average depth of this volcanic lake is due to the nearly symmetrical caldera formed 7,700 years ago during the violent climactic eruptions and subsequent collapse of Mount Mazama and the relatively moist climate that is typical of the crest of the Cascade Range.
The Western Rift, also called the Albertine Rift, is bordered by some of the highest mountains in Africa, including the Virunga Mountains, Mitumba Mountains, and Ruwenzori Range. It contains the Rift Valley lakes, which include some of the deepest lakes in the world (up to deep at Lake Tanganyika).
Vanderford Valley (Other English names: Vanderford Strath, Vanderford Submarine Valley Hungarian "Vanderford-selfvölgy") () is an undersea valley, named in association with the Vanderford Glacier, which reaches a depth of 2287 m (7,503 ft). This may be the deepest glacier-carved valley in the world.
The lake is across, with a caldera rim ranging in elevation from and an average lake depth of . The lake's maximum depth has been measured at , which fluctuates slightly as the weather changes. On the basis of maximum depth, Crater Lake is the deepest lake in the United States, the second-deepest in North America (after Great Slave Lake in Canada), and the ninth-deepest lake in the world. Crater Lake is often cited as the seventh-deepest lake in the world, but this ranking excludes Lake Vostok in Antarctica, which is beneath about of ice, and the recent depth soundings of O'Higgins/San Martín Lake, which is along the border of Chile and Argentina.
There are many examples of chalk dry valleys along the North and South Downs in southern England. Notably the National Trust-owned Devil's Dyke near Brighton covers some of downland scarp, and includes the deepest dry valley in the world – created when melting water eroded the chalk downland to the permafrost layer after the last ice age. The three-quarter mile long curved dry valley is around in height and attracts tourists with its views of Sussex, Hampshire and Kent.
Most of the industrial remains in the valley are the results of the endeavours of Joseph Treffry (1782–1850). Copper mining was booming in the area during the early 19th century, and Treffry was the owner of Fowey Consols mine, one of the deepest, richest and most important of the Cornish copper mines. The mine was situated to the east of the southern end of the Luxulyan Valley proper, and its site is part of the designated World Heritage Site. At its peak it was worked by six steam engines and 17 water wheels.
Mining was probably centuries old, with tin-streaming in the valley, when examples of deep-mined copper were recorded from the late 17th-century. Cook's Kitchen is recorded by 1690, as is Dolcoath, and on a 1748 map, mines are shown at Dolcoath and South Roskear. A copper foundry at Entral was started by Sampson Swaine and other gentlemen of Camborne in 1754, and Long Close, Wheal Crofty and Wheal Susan were mines operating in what is now the built-up area of Tuckingmill. The parish also contained what is said to be the greatest of all Cornish mines, Dolcoath and also the South Crofty Mine, which was at one time the deepest in the world as well as being the last tin mine in Europe, only closing in 1998.
The Arun River enters from Tibet at an elevation of about 3,500 meters (11,500 feet) and flows south across the district, forming one of the world's deepest valleys relative to 8,481 meter Makalu to the west and 8,586 meter Kangchenjunga to the east.
The valley is a long and narrow trough, it is long with a width averaging with some points narrowing to over most of the course before widening out to a delta when reaching the Dead Sea. Due to meandering the length of the river itself is . This is the deepest valley in the world, beginning at an elevation of below sea level and terminating at an elevation lower than below sea level. On both sides, to the east and west, the valley is bordered by high, steep, escarpments with the difference in elevation between the valley floor and the surrounding mountains varying between to .
Wast Water or Wastwater () is a lake located in Wasdale, a valley in the western part of the Lake District National Park, England. The lake is almost long and more than wide. It is a glacial lake, formed in a what is a fine example of a glacially 'over-deepened' valley. It is the deepest lake in England at . The surface of the lake is about 200 feet above sea level, while its bottom is over 50 feet below sea level. It is owned by the National Trust.
Following are the longest, widest, and deepest rifts and valleys in various worlds of the Solar System.
By 1897, the Calumet & Hecla's Red Jacket shaft had reached a vertical depth of 4,900 feet, making it the deepest mine in the world. The neighboring Tamarack mine became the world's deepest mine for some years; it was bought by Calumet & Hecla, and became part of the Calumet & Hecla system. The Tamarack/C&H remained the world's deepest mine until about 1915, when its vertical depth of 5,500 feet was exceeded by the 5,824-foot depth of the Morro Velho gold mine in Brazil. 
The eastern boundaries of the Tonga and Kermadec Plates constitute the subduction zone of the Pacific Plate, characterized by a trench about 2,000 km in length. The trench is continuous, but has different names for different sections: Hikurangi Trench, the Kermadec Trench and the Tonga Trench. The Tonga Trench is the second deepest trench in the world at about 10,800 m, with the deepest point, Horizon Deep, being the deepest point in the Southern Hemisphere and the second deepest point in the world, after the Challenger Deep in the Mariana Trench. The eastern boundary of the Kermadec Plate is also the site of the Kermadec Trench, which is the fifth deepest trench in the world at about 10,000 m. The eastern boundary of the Tonga Plate is one of the fastest subduction zones with a rate of up to 24 cm/yr.
There are hundreds of "holes" on Velebit. It has the largest and deepest caves in Croatia. The three-part "Lukina jama" cave is 1392 m deep, making it one of the deepest caves in the world, and the deepest in southeast Europe, while the "Slovačka jama" is 1320 m. What makes it unique is that it is completely vertical, steepest in the world. At the bottom of the pothole is a water course or siphon with branches that are still unexplored. A kind of leech was discovered in the pothole, which has been ascertained to represent a new species, genus and family; it has been named "Erpobdella mestrovi".