Wat Phao Khao or the “Monastery of the Burned Rice” was located on the city island in the eastern area at Ho Ratana Chai sub-district. The temple was situated north of Wat Suwan Dararam and east of Khlong Nai Kai presently called Khlong Makham Riang. Wat Phao Khao stood just opposite of Wat Ho Rakhang at the other side of the canal.
The monastery is mentioned in the Royal Chronicles of Ayutthaya. It was in this area that the Siamese army of Phra Maha Thep tried to regroup after their defense lines in front of Wat Kho and Wat Krabu were broken by the Burmese in their attack of Ayutthaya in 1569.
The Burmese principal effort seems to have occurred in the south east as the northern, western and southern flanks of the city were protected by the rivers, being a natural barrier. The eastern side of the city was easily prone to attack as no real defense line existed. The Pa Sak River did not change its course yet, and a large tract of land - only partially cut by some shallow irrigation canals - lie in front of the city. The troops of Prince Thammaracha from Phitsanulok and the Burmese Uparat (second to the King of Hongsa) advanced over Kaew Island (Crystal Island - the actual location of Wat Ko Kaew) towards the city.
The regrouping and consolidation of the Siamese army near Phao Khao Monastery did not succeed because Phra Maha Thep’s forces were so scattered that it was impossible to reform the defense lines. Phra Maha Thep’s army was routed again and the Burmese were able to enter the city, leading to the first fall of Ayutthaya. The event occurred on 30 August 1569.