6. 18 Hoang Dieu archeological monuments
This archaeological site is situated at 18 Hoang Dieu Street, Ba Dinh District, and is analyzed and divided into 4 zones, named A, B, C, and D by Archaeological Institute.
Zone A is located adjacent to Hoang Dieu Street. This area has been discovered with many important architectural traces, typically the trace “multi-room architecture” dating from Ly – Tran Dynasties, in an area of over 70m long and 18m wide which are evidently reflected through 40 column base stone pedestals, distributed in 10 rows, each row of 4 cylinders with 9 rooms. These remnants are located in the north of the archaeological area.
Zone B is located adjacent and parallel to Zone A. This area has been discovered with many large architectural foundation traces of Ly – Tran Dynasties with multi-space structure, construction techniques and reinforcement similar to Zone A. In the north of this area, at hole B16, archaeologist have found a ground of an architectural monad under Tran Dynasty with large column base lotus-shaped stone pedestal (column diameter of about 52 cm) are still in original positions.
Zone C is next to Zone B, adjacent to the campus of Ba Dinh Hall. This area has five new excavation pits. Although the excavation has been limited within a small area, in reconnaissance hole C3, archeologists have found architectural traces of Ly Dynasty with systems of large square column footing reinforced with gravels, bricks and pile systems and wooden pillars.
Zone D is located in the position of the old Ba Dinh Sports Centre, next to the Doc Lap Street and the Ba Dinh Hall premises. This area has been excavated with 7 pits (D1 – D7). In pits D4 – D6, there are architectural foundations of many periods overlaying on each other similar to Zone B. In which, there is an architectural ground of Ly – Tran Dynasties, clearly identified through the gravel footing under stone columns which reveals in an area of about 450m2 with 7 compartments.
7. Bac Mon (North Gate)
Northern Gate was built in 1805 on the foundation of Northern Gate under Le Dynasty with the architecture of watch tower gazebo – the watch tower was built on the wall of 8.71 m height, 17.08m width and with 2.48m walls.
The watch tower was built with wooden frames of eight roof style and four doors into four directions. The rampart was solidly built with stone and bricks; the rampart footing was fortified with stone. The gate was erected with a brick arch in which a horizontal bricks was interposed with a vertical brick. The size of bricks was 35.5 cm x 10 cm x 12 cm. The size of stone pedestal was from 38 to 86 cm.
Edges of the gate were rectangular, decorated with the image of lotus. The two wooden doors were renovated with the total area of 24m2 and the weight of about 16 tons, running on copper wheels weighing about 80 kg. At the outside of the gate, above the doors, there are Chinese characters curved in stone, meaning North Gate, decorated with the image of strings of flowers.
Currently, the watch tower gazebo is being restored partly for worshiping two province chiefs of Hanoi Citadel i.e. Nguyen Tri Phuong and Hoang Dieu who sacrificed for not being able to defend the citadel under the assault of French army.
Hanoi Flag Tower
8. Ky Dai (Hanoi Flag Tower)
Ky Dai or Hanoi Flag Tower was built in early Nguyen Dynasty (1805 – 1812) on the former foundation of Tam Mon Palace under Le Dynasty. Hanoi Flag Tower remains an undamaged and the most imposing structure in the entire Thang Long Imperial Vestige.
The whole architecture is 33.4m high from its basement up to the top including three tiers of 12m, column of 18.2m and observatory of 3.3m. If including the round base for flagging on top, the structure is 41.4m high.
The first tier has the length of each side of 42.5m, the height of 3.1m and two brick staircases. The second tier has the length of each side of 27m, the height of 3.7m with 4 doors facing four directions. Except the North one, the other three are inscribed with two characters relevant to its direction: East door – Nghênh Húc (To welcome dawn’s sunlight), South door – Hướng Minh (Directed to the sunlight), West door – Hồi Quang (To reflect light). The third tier is a square of 12.5m each side and 5.1m high. There is a spiral staircase leading from the first to the third tier.
The part above the third tier is a column with 8 fringes narrower to the top. Each fringe is 2.13m wide and 18.2m high. The spiral staircase consists of 54 steps. It is lightened and ventilated by 39 flower-shaped and 6 fan-shaped windows which scatter along the fringes with 5 or 6 on each.
On top of the tower is an octagonal observatory of 3.3m high with 8 doors in 8 sides. In the middle of it, there is a round base of 0.4 meter in diameter and 8m high up to the top where the national flag is fixed.
On October 10th, 1954, the red flag with yellow star, the National Flag, flied on the top of Hanoi Flag Tower for the first time which was recognized as the historical monument in 1989.