Drepung lies eight kilometers ( five miles) west of Lhasa on a main road, then three kilometers ( two miles) north on a steep , unpaved road. Its name means Rice Heap, after its jumble of white buildings piled up against Mt Gambo Utse. This was the biggest and richest monastery in Tibet. Its lamas, who helped to train each young dalai lama, could guess how a new god-king would rule- as a leader or as a tool of the regent.

Drepung was founded in 1416 by a disciple of Tsong Khapa, with a noble family as patron. The Fifth Dalai Lama enlarged it and ruled there while the Potala was being built. At its height, Drepung had over 10,000 monks. It governed 700 sub-sidiary monasteries and owned vast estates.

Of the 6,000 monks who lived here in 1959, half, including all the high lamas, fled with the Dalai Lama. The rest went home, took up trades, and married. A handful of elderly monks stayed on at the monastery, laboring on a 20- hectare ( 50- acre) farm that the Chinese let them keep. Today, about 400 monks and novices live there, turning a profit from their orchards, which produce the best apples in Lhasa.

The monastery was divided into four tantric colleges which, at the highest level, specialized in different branches of knowledge. Each had its own chanting hall, dormitories, kitchens and offices. The entire monastic community assembled only for special ceremonies and festivals.

The changing halls are all built on a similar plan, facing south with a courtyard in front. A big vestibule, with stairs to the roof at its east end, had large murals that typically include the Four Heavenly Kings and the Wheel of Life. These are worth careful study. The chanting hall, hung with thangkas and ' victory banners', has closely spaced pillars with rows of cushions between, each holding a monk's robe and cap. Murals decorate the walls. Stairs on the left lead to the roof. Walk along the north wall in a clockwise direction. It is often dark, so bring a flashlight. The roof contains a hollow pavilion whose windows illuminate the chanting hall beneath. It is surrounded by a painted gallery. The higher roof levels hold chapels. The top level, supporting the golden finials, has splendid view.

The gravel road approaching Drepung winds up through orchards and groves ( full of hoopoes in spring and summer) before arriving at a car park; at the back is a small shop, and to the right are food stalls, a garage that functions as the monastery's apple shop in the autumn, and a restaurant serving simple Tibetan fare- thukpa (noodles), momos (dumplings) and sweet tea.

Stone steps lead up to the monastery city, arriving first at the chanting hall of Loseling College. Splendid murals on the south wall show a finely detailed Chenrezi in a circle of hands and eyes ( left ) and Yamantaka with the Eight Guardians ( right). Gold stupas on the altar and in the chapel are tombs of the Second, Third and Fourth dalai lamas. Butter and tsampa sculptures fill a glass case on the altar. The chapel behind has fine drawings on its plain red walls, and in a glass case is a doll-size oracle in full regalia, with crown and armour, prophesying with open mouth. The oracle appears in various forms all through the monastery, recognizable by the circular mirror on his chest.

The monks do not mind visitors going clockwise around the edge, if chanting is going on, but discretion should be used in taking photographs. Drums and cymbals sometimes accompany the chanting. Periodically, a bell sends teenage novices dashing out for jugs of butter tea to fill the wooden bowls of older monks. A kitchen just east of the chanting hall uses medieval stoves and gigantic churns, urns, cauldrons and utensils. Uphill to the west is the Main Assembly Hall ( Tshomchen). East of the entrance, there is a small porch, instead of a vestibule, with a dais overlooking the courtyard. The dilapidated, half-empty interior is redeemed by h huge thank, the old weapons chapel. The roof, housing Drepung's treasures, has on its west side a chapel fronted by a covered porch. This contains the Holy of Holies, a giant gilded Buddha, whose head and chest alone are visible. The cluttered chapel also holds, nearly hidden under white scarves, a sacred conch shell with counter-clockwise whorls. Pilgrims come here to prostrate themselves. To the east is a chapel containing oracle dolls said to have spoken to special lamas in olden times and Tsong Khapa's tooth in a gold reliquary.

Behind this building is the carved rock face on which Drepung was founded. It now forms the wall of a little temple with white stupas on wither side. The stick with which the founder beat his disciples is kept here in a silver scabbard by a lama who uses it to bless pilgrims, tapping them on their backs and shouldered with mock ferocity.

The small chanting hall of Ngagpa College nearby deserves a visit for the exquisite gold drawings on its red doors, portraying the history of the dalai and Panchen lamas. Straight down the hill from there is the Garden Podrang, a three-tiered building from which the Fifth Dalai Lama reigned while the Potala was under construction. It should be entered from below to get its full effect. Steep steps lead up from its unimpressive front yard to an inner courtyard and a sudden, stunning view of its majestic facade.