Question: To which mountain range belong both Istor-o-Nal in the Hindu Kush and Mount Everest in Nepal and Tibet?
Context: Everest Base Camp is either of two base camps on opposite sides of Mount Everest (It could also be any Everest base camp on given route, but this is less common since the two main routes became standardized).  South Base Camp is in Nepal at an altitude of 5364 m ( ), and North Base Camp is in Tibet at 5150 m ( ).  These camps are rudimentary campsites on Mount Everest that are used by mountain climbers during their ascent and descent.  South Base Camp is used when climbing via the southeast ridge, while North Base Camp is used when climbing via the northeast ridge. The 1922 British Mount Everest expedition was the first mountaineering expedition with the express aim of making the first ascent of Mount Everest.  This was also the first expedition that attempted to climb Everest using bottled oxygen.  The expedition would attempt to climb Everest from the northern side out of Tibet.  At the time, Everest could not be attempted from the south out of Nepal as the country was closed to Western foreigners. The Kushan Pass or Kaoshan Pass (el.  about 4,370 m or 14,340 ft) is a mountain pass just west of the famous Salang Pass (3,878 m. or 12,723 ft.) in the Hindu Kush mountain range of northern Afghanistan.  These two passes provided the most direct, if difficult, routes across the imposing east-west wall of the Hindu Kush mountains which divide northern Afghanistan or Tokharistan from Kabul province, which is closely connected to southern Afghanistan and Pakistan.  Nowadays, the Salang tunnel constructed by the Soviets in the 1960s, and the paved road through it make it by far the easiest route through the Hindu Kush Mountains. The 1996 Mount Everest disaster occurred on 10–11 May 1996, when eight people caught in a blizzard died on Mount Everest during attempts to descend from the summit.  Over the entire season, 12 people died trying to reach the summit, making it the deadliest day and year on Mount Everest before the 16 fatalities of the 2014 Mount Everest avalanche and the 18 deaths resulting from avalanches caused by the April 2015 Nepal earthquake.  The 1996 disaster gained wide publicity and raised questions about the commercialization of Everest. Istor-o-Nal or इस्तोर-ओ-नल is the third highest mountain in the Hindu Kush, in the Chitral District of the North-West Frontier Province of Pakistan.  It is the 68th highest independent peak in the world.  It crowns a massif with eleven peaks of elevation more than 7000 m .  The peak is located a few kilometres northeast of Tirich Mir (the highest mountain in the Hindu Kush), across the Tirich Glacier.  Because Istor-o-Nal is behind the higher peak of Tirich Mir from many viewpoints, it is not easily visible and therefore not well known. Mount Everest, known in Nepali as Sagarmāthā and in Tibetan as Chomolungma, is Earth's highest mountain, located in the Mahalangur Himal sub-range of the Himalayas.  The international border between China (Tibet Autonomous Region) and Nepal runs across its summit point. Gangga (or "Tingri" according to name of region) (Tibetan: སྒང་དགའ་ , Wylie: sgang dga', Chinese: 岗嘎镇 ; Pinyin: gǎnggā zhèn) is a town in southern Tibet.  It is in Tingri County, Shigatse Prefecture with a population of around 523.  It is often used as a base by mountain climbers preparing to ascend Mount Everest or Cho Oyu.  Tingri Shelkar (Dring ri Shel dkar) is a small town approximately 60 km north-west of Mount Everest and just over 50 km from the Nepali border in the Tibet Autonomous Region of China.  It is at an altitude of about 4,300 metres (approx. 14,107 feet).  The old Shekar Dorje "Dzong", or fort, is above the new town and used to enclose Shekar Chode, a Gelug monastery which was completely destroyed but is being restored.  It is known for its spectacular views of Mount Everest, Mount Lhotse, Mount Makalu, and Cho Oyu, which comprise four of the six highest mountains in the world. Kush is a strain of" Cannabis indica".  The origins of Kush "Cannabis" are from landrace plants mainly in Afghanistan, Northern Pakistan and North-Western India with the name coming from the Hindu Kush mountain range.  "Hindu Kush" strains of "Cannabis" were taken to the United States in the mid-to-late 1970s and continue to be available there to the present day. Kuh-e Bandaka (Pashto: کوه بندکا) or Kohe Bandaka, Koh-i Bandaka, Bandako, or incorrectly "Koh-i-Bandakor") is one of the highest peaks of the Hindu Kush mountain range in northeastern Afghanistan.  It is northeast of Kabul and west of Chitral.  Separated by a relatively low pass from the core of the Hindu Kush, it is the highest mountain entirely within Afghanistan, and the most topographically prominent peak in all of Afghanistan. After World War II, with Tibet closing its borders and Nepal becoming considerably more open, Mount Everest reconnaissance from Nepal became possible for the first time culminating in the successful ascent of 1953.  In 1950 there was a highly informal trek to what was to become Everest Base Camp and photographs were taken of a possible route ahead.  Next year the 1951 British Mount Everest reconnaissance expedition reconnoitred various possible routes to Mount Everest from the south and the only one they considered feasible was the one via the Khumbu Icefall, Western Cwm and South Col.  In 1952, while the Swiss were making an attempt on the summit that nearly succeeded, the British practised their high-altitude Himalayan technique by attempting Cho Oyu, nearby to the west.
Answer: Himalayas