It is commonly known as a flagpole, but viewed from the Imperial City; it is really a huge structure of three flat-top pyramids, one lying on top of another. It was built during Emperor Gia Long's reign, in 1807, and later improved by his son, Emperor Minh Mang.



According to the Thuc Luc (Nguyen Dynasty's Chronicle), the flag-tower is 17.40m high and consists of three terraces. The first is 5.60m high, the second, 5.8m, and the third, 6m. The higher the terrace is, the smaller its surface is. On the third terrace, are 8 little buildings housing one canon each and two sentry-boxes at opposite ends. The 29.52m flag-staff was originally made of wood. It was replaced by a new one in 1846 by Emperor Thieu Tri and again in 1914, with French assistance, with a cast-iron one after having been destroyed by a typhoon. Forty-three years later, after the return of the French colonialists (1947), the staff was again destroyed. So it was in 1948 that a 21m concrete staff was erected. In feudal times, a yellow flag flapped everyday on top of the staff. It was replaced with a larger one on festive occasions (The Nam Giao Offering Ceremony, for example). Made of wool or velvet, this 4m by 3.6m flag was brocaded with a dragon design in its center and fringed with serrated lace.