The Gandan Monastery(Chinese:甘丹寺；pinyin:gāndānsì) lies in Dagze County 60 kilometers to the east of Lhasa. It stands at an altitude of 3,800 meters (12,467 feet) above sea level! Gandan Monastery is one of the earliest and largest Buddhist monasteries in Tibet, and stands atop of the six famous temples of Gelugpa - a branch of Tibetan Buddhism. Its significance as a religious, artistic, political and cultural relic led to it being preserved by the National Key Cultural Relic Preservation scheme in 1961, and is now known as being one of the 'Three Great Temples', together with the Sera Monastery and the Drepung Monastery. Every year, one of the grandest of Buddhist activities - Buddha Painting Unfolding Festival - is conducted in the monastery, attracting thousands of visitors and disciples.

Gandan means happiness and contentedness in Tibetan. The Gandan Monastery, the first and foremost Gelupka monastery, was built in 1409 under the supervision of Tsong Khapa, founder of the Gelug Sect of Tibetan. In the early 15th century, Tsong Khapa called for the Reformation of Religion, advocating the rooting out the previous disadvantages in religious orders and initiated the Gelugpa. This sect also became known as the Yellow Hat sect, as its disciples were always wearing yellow hats. This order went on to become the biggest sect in Tibetan Buddhism, leading to Tsong Khapa establish the Ganden Monastery. Since dharma is essential to the teachings of the sect, the whole layout of the monastery is built on its principles.

The main buildings include the Coqen Hall, the Chamber of Tsong Khapa, and the Yangbajian Zhacang (colleges for studying the sutras).
The three-story Coqen Hall is the monastery's main hall, large enough to hold a gathering of 3,000 lamas, who use the hall for sutra recitation. The main hall was not completed until 1417, two years before Tsong Khapa died, but after having announced his disciple, Gyeltsab Je, as the new leader of the Gelug Sect or Gandain Chiba.
Tri Thok Khang is one of the earliest Buddha Halls in the Ganden Monastery, and once served as Tsong Khapa and other tripas' bedchamber. Originally built in 1409, and added onto in 1720, it was once adorned with luxurious gilded bronze bricks.
The monastery possesses two Zhacang (or Tantric colleges) - Xaze and Jamze. Both of these cover an area of nearly 1,000 square meters (1196 square yards) and are capable of holding 1,500 worshipping lamas.

The name Gandan Chiba refers to the head abbot of the Gandan Monastery. Since the Gandan Monastery is the ancestral monastery of the Gelug Sect, the Gandan Chiba is also the head abbot of the Gelug Sect. He is next only to the Dalai Lama and the Pachen Erdeni in terms of status in Tibetan Buddhism.
In the following years, Dama Bergin, a disciple of Tsong Khapa, built a silver stupa that now contains Tsong Khapa's remains. It was the 13th Dalai Lama who rebuilt this stupa and wrapped it in gold leaves.
When viewed from a distance, the Gandan Monastery looks very much like a castle. It was listed as one of Tibet's cultural relics under the special protection of the State in 1961.