The octagonal City is a well-preserved ancient city ruins in the Ganjia Grasslands of Xiahe County, 35 kilometers north of Xiahe County. It’s famous for its eight angles. The enclosing wall is a hollow cross, commonly known as “Ka Erkang” in Tibetan, which means million words City.
The Octagonal City was a very important transportation cross of Gansu and Qinghai in ancient times. Also it is a military stronghold that successive central governments compete for with Tuyuhun, Tibetan and Luo dynasty.
The Octagonal City is 2193.4 meters long with an area of 300 acres. There are moats outside the city and another city outside the north gate. From the perspective of architecture art, this city is a strong-defensive castle. The special architectural form is rather rare in China’s ancient cities even in the world. Historical archaeological survey also shows that the Octagonal City preserve enormous cultural relics of Southern and Northern Dynasties and Sui, Tang, Song, Yuan, Ming and Qing era. It is a place full of history traces deserving visiting.