The history and date of the establishment of Wat Prasat are not known.
The monastery is shown on Phraya Boran Ratchathanin’s map of 1926 CE and the 1993 and 2007 CE FAD maps.
Wat Prasat is in geographical coordinates: 14° 20' 46.6" N, 100° 35' 04.1" E.
There are five sites with the name Wat Prasat. The four others are in the southern part of the city in the Pratu Chai Sub-district, in the western part of the city in the Pratu Chai Sub-district, in the Hua Ro Sub-district and the Khlong Sra Bua Sub-district.
Footnotes:
(1) Khlong Thanon Tan or the Canal of the Sugar Road. It flows through the Kramang and Suan Phlu sub-districts. The canal links Khlong Khao San with Khlong Suan Phlu and the Pa Sak River and probably gave access earlier to Wat Yai Chai Mongkhon. No monasteries were situated along its banks. The canal forms an island called "Ko Kaeo" or "Crystal Island", with a stretch of the Pa Sak River and Khlong Khao San. Ko Kaeo was an important battleground during the wars with the Burmese. The canal is filled in and is only used as a water drainage canal (heavily polluted).
(2) Khlong Khao San, or the Canal of the Milled Rice, flows on the border between Phai Ling and Suan Phlu sub-districts. It links Khlong Dusit with the Pa Sak River. At par with Khlong Hantra, Khlong Kramang and Khlong Dusit, this canal was probably once a stretch of the Pa Sak River. This canal is also referred to as Khlong Ko Kaeo.
(3) The Ayutthaya monasteries were sacked and plundered by the Burmese and further dismantled after the fall of Ayutthaya to reconstruct the Siamese capital in Bangkok. Most parts of the wall and the forts were dismantled in the reign of King Rama I (1782 - 1809 CE), who had the bricks taken to be used in constructing the city walls for the new capital in Bangkok. In 1784 CE, bricks from the ruins of Ayutthaya were used to build a barrage in the Lat Pho Canal at Phra Pradaeng to halt the intrusion of saline water farther inland. Another round of collecting building material occurred in the reign of King Rama III (1824 - 1851 CE) when remaining bricks and laterite stones, including those of the Thamnop Ro causeway and the Elephant Bridge, were sent down to Bangkok to be used in the construction of a giant stupa, a copy of Ayutthaya's Chedi Phukhao Thong, called Wat Saket which collapsed into rubble. Ayutthaya's temple bricks were also used to strengthen the bed of the Bangkok - Ayutthaya - Lopburi railway track at the end of the 19th century. When, in the last century, the demand for antiques increased, and the amulet markets mushroomed, Ayutthaya's ruins were plundered one more time. During the fifties and early sixties, witnesses recount, it was common for locals in the Ayutthaya area to collect the bricks of the ruins. The bricks were locally used to help expand other temple sites but were mostly sold to contractors and shipped on a large scale as there was a demand from Bangkok. Trucks and boats from Bangkok collected the bricks at 20 Baht a load.
References:
[1] Cushman, Richard D. & Wyatt, David K. (2006). The Royal Chronicles of Ayutthaya. Bangkok: The Siam Society. p. 65.