This is at Drepung Monastery during Shoton Festival. Usually this is the first of large silk thangkas to be unrolled. Drepung Monastery, located at the foot of Mount Gephel, is one of the "great three" Gelukpa university monasteries of Tibet. The other two are Ganden and Sera.
Drepung is the largest of all Tibetan monasteries and is located on the Gambo Utse mountain, 5 kilometers from the western suburb of Lhasa.
Drepung Monastery was founded in 1416 by Tsongkapa's disciple Jamyang Choeje. It was the home of the Dalai Lamas before the Potala Palace was built in the 17th century. Resembling a heap of white rice from a distance, it was dubbed "Monastery of the Collecting-Rice" (Drepung Gompa) in Tibetan.
Freddie Spencer Chapman reported, after his 1936-37 trip to Tibet, that Drepung was at that time the largest monastery in the world, and housed 7,700 monks, "but sometimes as many as 10,000 monks.