Text by Tricky Vandenberg - February 2010
Updated March 2013
Pom Sat Kop or the Fortress of the Frog was one of the sixteen fortresses (1) along the city walls of Ayutthaya. Sat Kop fortress guarded the
north-western part of the city.  The fortress was situated at the present military barracks and stood opposite Hua Laem (spear head, sharp point), a
cape formed at the confluence of the
Chao Phraya River (before the Bang Kaeo River) and Khlong Mueang (before the Lopburi River).

Prince Damrong situates the construction of Sat Kop and
Pom Phet (a fortress in the south-east of the city, just opposite Bang Kaja) during the reign
of King Maha Chakkraphat (r. 1548-1569), shortly after the first attack of Ayutthaya by the Burmese in 1549 [1]. King Chakkraphat realized that
Ayutthaya had entered the age of the gunpowder and large guns came to dominate the war theater and thus strengthened the defenses of the city by a
series of construction works: city walls were reinforced and redone in brick (brick does not shatter on impact from a cannon ball as stone does); a
new northern moat was dug to protect the northern part of the city - the
Maha Nak Canal; and walled fortresses were built along the city wall, mostly
at waterway intersections. [2]

Sat Kop is named in the Royal Chronicles of Ayutthaya as the "Fort behind the Frogs". The Burmese occupied in 1766 positions at
Ban Pom and
Wat Ka Rong and started to establish a stockade at Wat Phukhao Thong. Phraya Sri Suriyaphat who commanded the Sat Kop Fortress, had a large
gun called the Grand Black King of Death, prepared to shoot at the new Burmese position. The King of Death was loaded with a double charge of
gunpowder and two canon balls. Only one round was fired and the large gun was temporary disabled. Afterwards the Siamese managed to use the
gun again and succeeded in sinking two Burmese fighting boats. [3]

The fortress consisted of two bastions connected by a curtain with battlements. The Sat Kop Gate was situated in between the two bastions. On the
road in front of the Sat Kop Gate there was a fresh market. [4] At the south side of the fort was the mouth of
Khlong Fang which ran into the main
Khlong Tho. Wat Khok was located behind the fortification.

Most parts of the wall and the fortresses were dismantled in the reign of King Rama I, who had the bricks taken to be used in the construction of the
new capital in Bangkok. [5]


(1) Not taken into account the fortresses surrounding the Grand Palace.


[1]  Our Wars with the Burmese - Prince Damrong Rajanubhab (1917) - Re-edited White Lotus (2001) - page 66.
[2] A History of Siam - W.A.R. WOOD (1924) - page 114.
[3] The Royal Chronicles of Ayutthaya - Richard D. Cushman (2006) - page 512 / Source: Phan Canthanumat, British Museum, Reverend
Phonnarat & Royal Autograph.
[4] Markets and Production in the City of Ayutthaya before 1767: Translation and Analysis of Part of the Description of Ayutthaya - Chris Baker -
Journal of the Siam Society, Vol. 99, 2011 - page 65.
[5] A History of Siam - W.A.R. Wood (1924) - page 273.