Wat Mo Hon, or the Monastery of the Astrologer, was located off the city island in the southeastern area of Ayutthaya in the Phai Ling Sub-district. The temple was part of a cluster of temples east of Wat Yai Chai Mongkhon.
Rojana Road runs north and east, an unidentified site stands south, and Wat Maha Thalai is west,
No traces of the temple are left on ground level, but it was on a small mound visible on the Ayutthaya aerial flood map from November 2011 CE.
Wat Mo Hon was situated on the west bank of Khlong Pho (1), a canal splitting off from Khlong Khao Mao, east of Wat Krasang.
The site is only mentioned on a Fine Arts Department (FAD) map drafted in 1993 CE.
To my knowledge, no excavation has been performed by FAD on this site.
Wat Mo Hon was approximately in geographical coordinates: 14° 20' 54.72" N, 100° 36' 8.10" E.
Footnotes:
(1) Not confirmed as yet, but Khlong Pho could have been connected to Ban Pho in the Bang Pa-In District and exited into the Chao Phraya River opposite Ko Phra in a location called "Ban Kedam" by the Dutch or "Krasen" on 17-18th C maps.