Katok Monastery (kaḥ thog) - aka Katok Dorje Den. One of the Six "Mother" Nyingma Monasteries. It was founded by Katok Dampa Deshek, younger brother of Phagmodrupa, in 1159. After the original monastery had fallen into disrepair, a new monastery was built on the site in 1656 by Tertön Düddul Dorje (1615-72) and Rigdzin Longsal Nyingpo (1625-92). There were approximately 800 monks at the monastery before the Chinese invasion of Tibet.
The monastery had a reputation for fine scholarship and produced some of the greatest scholars in Tibetan history, such as Katok Rigdzin Tsewang Norbu (1698-1755) and Getse Pandita Gyurme Tsewang Chokdrup (b. 1761). More recently, Katok Situ Chökyi Gyatso and Khenpo Ngawang Palzang, aka Khenpo Ngakchung, were among the greatest lamas associated with the monastery.