Fortification of Bangkok, tracking Bangkok’s Forts, City Walls and Moats
Fortification of Bangkok
Tracking Bangkok’s Forts, City Walls and Moats
Also see: FAM tour of Thailand
Today Bangkok is a modern city with a few ancient temples, but on closer inspection one can find an unique series of defensive mechanism which one protected the ancient city. The defensive mechanism consisting of forts, defensive walls and moats, which were constructed over a period of several centuries.

Phra Sumen Fort, Bangkok (Photo edit Deepanjan Ghosh)
The structures started coming up during the late Ayutthaya Kingdom (1351 – 1767) and continued till the present Rattanakosin Kingdom (started in 1782). Bangkok underwent rapid modernization beginning in the late 19th century, and by the 1920s most of the city’s original forts and walls had been demolished to make way for the construction of roads and buildings.

Map of Bangkok’s Fortification (Source Wikimedia Commons)
Today only four of Bangkok’s ancient forts remains along with a small stretch of the defensive wall. Luckily most of the defensive moats have survived and plays an important role in Bangkok’s present daily life.

Wichaprasit Fort, from Chao Pharaya River, Bangkok (Source: Wikimedia Commons)
Among the four surviving forts of Bangkok is the Wichaprasit Fort. It is the only pre Rattanakosin period fort of Bangkok.
The Ayutthaya kingdom had there capital in Ayutthaya about 80 km north of Bangkok and the Wichaprasit Fort only acted as a guarding post in the Chao Pharaya River.
Built in 1688 the fort lies on the western bank of Chao Pharaya River and at the confluence of Bangkok’s Yai Canal.
It is located next to Wat Arun (the temple of the dawn). Today the fort is the headquarters of Thai Royal Navy and is best viewed from boats sailing along the Chao Pharaya River.
In 1767 the Ayutthaya Kimgdom was over thrown by Taksin, who set up in capital at Thonburi, on the western bank of Chao Pharaya River. Later he extended his capital on the east bank (present day Bangkok) and dug moats and constructed city walls to protect it. The canal on the east bank is known Old City Moat.

Mahakan Fort, Bangkok
Sadly Taksin’s rule was short and he was overthrown in 1782 by Rama I, the founder of the Rattanakosin Kingdom.
He shifted his capital to the right bank and had a outer moat (Khalong Maha Nak) dug, which created the Island of Rattanakosin.
He had the new fortifications rebuilt along these new boundaries, using materials salvaged from Taksin’s old city walls and the ruins of King Narai’s old fort, as well as the ruins of Ayutthaya’s fortifications.
Rama I’s city walls measured 7.2 kilometres in length, encircling an area of 4.142 km2. Fourteen defensive polygonal forts were built along the walls, and 63 gates provided access to the walled city.
By the mid-19th century, Rattanakosin’s walled city had become overcrowded, and King Rama IV ordered the construction of Phadung Krung Kasem Canal in order to expand the city limits. Eight new star shaped forts were built in 1852 to guard the new boundary, seven along the canal, and one on the opposite bank of the river to the canal’s mouth. Defensive walls, outdated by then, were no longer built

Phra Sumen Fort, Bangkok
Out of the former fourteen only two have survived. From Rama IV’s fort only one have survived. The surviving forts from the former are Mahakan Fort (Map: Marked 4 in polygon) and Phra Suman Fort (Map: Marked 1 in polygon). The lone surviving fort from Rama IV is Pong Patchamit Fort (Map: Marked 1 in star).
Phra Sumen Fort is the northernmost of Rattanakosin’s original forts, located at the mouth of Khlong Rop Krung (outer moat) where it meets the river. The octagonal fort is built of masonry on a 2-metre (6 ft 7 in)-deep spread footing foundation. It is 45 metres (148 ft) in diameter, and has a height of 10.5 metres (34 ft) measured to top of the sema-shaped battlements of the upper level.

Portion of Old City Wall, Bangkok
The fort has rectangular battlements on the lower level, and is topped by a roofed heptagonal tower, which collapsed sometime during the reigns of kings Rama V to Rama VII and was rebuilt in 1981 to celebrate the bicentennial of the city’s foundation.
The Mahakan Fort lies at the junction of the two canals the other moat (Khalong Maha Nak) and Khalong Sean Seap (Also see: Khalong Saen Saep Express Boat) and in the shadows of Wat Saket and the Golden Mount.
The fort, also octagonal in shape and in three levels, has a diameter of 38 metres and a height of 19 metres, measured to the roof of the octagonal tower. Mahakan Fort has rectangular battlements on both its lower and upper levels, while the connected 180-metre (590 ft)-long section of the city walls features sema-shaped battlements. The fort and walls were also restored in 1981 for the city’s bicentennial

Old City Moat from Pa Kun Bridge
Pong Patchamit Fort is the lone surviving Rama IV fort and lies on the west bank of Chao Pharaya River.
Today, only a small section of the fort remains (an estimated area of 852 square metres out of the original 10,233 square metres.
Today the only remains of Rama I’s city wall can bee seen in front of Wat Bowonniwet. The wall here is 1.8 metres (5 ft 11 in) thick and 6 metres (20 ft) high. Also featuring sema-shaped battlements, steps beside the gate provided access to the top of the wall. The gate’s 12-metre (39 ft) pointed roof, which had earlier collapsed, was rebuilt in 1981 using photographic evidence from the reign of King Rama V.
Note: I visited Thailand as part of a FAM trip organized by Tourism authority of Thailand (TAT) and Thai Airways.
Special Thanks:
- Aso Lori (TAT, New Delhi) and Sajid Khan (Thai Airways, Kolkata)
- My fellow FAM participants Amit Sachdev (Unique Air Travels), Sanjay Kr Kothari (Just Holidays), Vandana Arya (Gainwell Leisure Holidays), Piyush Banerjee (Discovery Holidays), Asif Alim (Neptune Holidays) and Nandini Gangully (T2, The Telegraph)
Nice write-up on an unusual aspect of Bangkok.
Thanks Anushtup