Lhasa is one of the highest cities in the world at an altitude of 3650 meters. Its terrain is high in the north and low in the south, and it inclines from east to west. The south-central part is the valley plain in the middle reaches of Lhasa River, a tributary of Yarlung Zangbo River, with flat terrain.

The basic features of the Potala Palace in Lhasa are mainly the white palace rebuilt during the period of the Fifth Dalai Lama in A.D.17th century and the red palace built after his death. "Since then, the Dalai Lama has expanded one after another, and finally the Potala Palace has today's scale."

The Potala Palace was built in the 7th century A.D. during the period of Songzan Gambo, the king of Tibet, with a history of 1300 years. At the beginning of the 7th century, after Songtsan Gambu moved to Lhasa, three nine-story thousand palaces were built on Hongshan, named Potala Palace, in order to marry Princess Wencheng of the Tang Dynasty.

There is a triple siege inside and outside Hongshan, and there is a silver-copper bridge between Songzan Gambu and Princess Wencheng Palace. Outside the east gate of Potala Palace, there is a horse farm in Songzan Gambu. When the Tubo dynasty established by Songtsan Gampo perished, most of the Potala Palace was destroyed by war.

Extended data:

Most of the Lhasa River basin is mountainous, with towering peaks and steep slopes, and the terrain inclines from north to south. There must be a small-scale modern glacier in Nyainqentanglha Mountain. Most tributaries on the right bank of the basin originate from glaciers, and most tributaries on the left bank originate from lakes or swamps.

The Lhasa River is V-shaped in the valley above Tanggu in Linzhou County, and widens to the valley below Mozhugongka County, with a width of about 1- 1.5 km. The floodplain began to appear, and the vegetation on the floodplain was good. This section of the river is relatively regular, with three continuous terraces distributed on both banks.

The third terrace is 40-50 meters higher than the river, and the surface is sandy topsoil with a thickness of 50-80 cm. It is a good natural pasture with lush grass. The second terrace is 20-30m higher than the river surface; The first terrace10-20m is higher than the river surface, and most of it has been cultivated.

Both banks of the river are valley alluvial plains with a width of 1- 10km, and the cultivated land area is about 570,000 mu. These areas have mild climate, flat terrain, thick soil and abundant water resources, and are one of the main grain producing areas in Tibet.

Baidu Encyclopedia-Lhasa