This fort that remains almost intact while ruins of the other forts which had been destroyed are visible around the city island. This fortress, also known as Phom Phet Pairote, is situated on a site known as Bangkaja where the Maenam Chao Phraya and the Maenam Pasak meet to form the south-west corner of the city island. This large fortress is thought to have been built during the reign of King Mahathammaracha following the loss of Ayutthaya to the Burmese for the first time in 1549. The original earthen parapet was strengthened with brick.