Sera monastery is the second biggest Gelugpu learning center, founded in 1419 by Chamchen Choeje Sakya Yeshe at the base of the hill just north of Lhasa. Originally Tsongkhapa stayed in retreat in a hermitage above Sera monastery. There are three main colleges in Sera with many Khagtsens within each of them. The three collages are, Je collage, Mey collage and Ngakpa collage.
Traditionally the number of monks in Sera is supposed to be 5,500. But at time there used to be up to 10,000 monks coming from every corner of Tibet. In terms of study or learning, it is similar to Drepung and Gaden. They all study the same Buddhist subjects in a systematic way.
Apart from the usual statue of Buddhas, Boddhisattvas and Dharma protectors, the main relics of Sera monastery Sera are unique meditation deity called Hayagriva, or the “horse-headed” deity, and a ritual Kilaya dagger. This statue and relics are considered to be very holy and people come specially to receive their blessing. Lhasa residents believe this deity can cure mental disease and clear obstacles so they will bring their small children for protective blessings. Sera monastery also has a debate courtyard where monks debate on specific points of Buddhist philosophy or logic. This is an important learning method in many Tibetan Buddhist monasteries, and the courtyard at Sera is open for tourists to view the lessons in action.