Yumbulagang Palace, (Yumbulakhang Palace) is the oldest palace in Tibet. It is also the oldest monumental structure in Tsedang. It was believed to be that King Nyatri Tsenpo descended from heaven to build this palace in 2nd century BC. Myths say that it is the founding of Tibetan civilization.

The Yumbulagang complex, positioned dramatically on the crest of a hill, consists of three components: the tower, the chapels and the monks'quarters. The three-storied tower, located at the east of the complex, is only 11 meters high. The main chapel building was also originally three stories high. However, only two of these storeys were rebuilt during the reconstruction in 1982. Of these, the first is dedicated to the historical Kings of Tibet and the second to local Buddhist deities. The final component of the structure, the monks'quarter, is located to the south of the chapel building. The first floor were for the Nyingma sect monks, whose duty were to upkeep the castle and chapel, while the second floor room, adjacent to the chapel's second floor, was reserved for the Dalai Lama.

Not far from the ancient castle is a plot of land shaped like a scythe (when viewed from the air), and enclosed by low walls. This is known as Zorthang, Scythe Plain, and is reputed to be the first cultivated field in Tibet. It is a tradition for pilgrims and farmers alike to collect soil from this place and to sprinkle it on their own plots to ensure a good harvest. Each year at sowing time small community of monks, still at Yumbulagang, conduct rituals to propitiate its earth spirits.