Wat Jom Thong, or the Monastery of the Golden Peak, was located on Ayutthaya’s city island in the western area of the Pratu Chai Sub-district. (1)
The site is only indicated on a 19th-century map by an unknown surveyor. The monastery was situated on the north bank of Khlong Tha Phra, between Wat Lanthom Noi and Wat Chang. (2)
There are no traces anymore visible of the monastery above ground level.
I think it would be unjust to conclude that there were only monasteries situated at the origin and near the mouth of Khlong Tha Phra and nothing in between them. There should have been more monasteries along this canal, as indicated by the 19th-century map. I presume this area was already cleared of temple ruins before Phraya Boran Rachathanin arrived in Ayutthaya. Phraya Boran (1871-1936 CE) was the Superintendent Commissioner of Monthon Ayutthaya from 1925 till 1929 CE but occupied important functions since 1896 CE in Monthon Ayutthaya.
Historical data about the monastery and its construction are unknown.
The 19th-century map indicates the presence of a chedi.
The site must have been in geographical coordinates: 14° 20' 49.61" N, 100° 32' 53.79" E.
Footnotes:
(1) There was a defunct monastery with a similar name on the banks of Khlong Chang Maha Chai.
(2) Khlong Tha Phra, also known under the name Khlong Klaep, is a defunct canal of which some stretches still can be seen today. The canal had its mouth at the former Lopburi River, today the Chao Phraya River, and ended in the east by joining Pratu Thep Mi Canal with a zig-zagging canal before reaching the gate of Pratu Thep Mi. Other evidence seems to suggest that in fact, this canal continued eastwards in a straight line to join the Nai Kai Canal.