Wat Hoi Khong, or the Monastery of the Apple Snail, was located on the city island in the southwestern area of Ayutthaya in the Pratu Chai Sub-district.

The former monastery was situated in the Somdet Phra Sri Nakharin Park, north of the restored ruin of Wat Wang Chai and east of Wat Sakae (defunct).

It was formerly located on the bank of an ancient canal system that in recent times had been altered by the construction of the Somdet Phra Sri Nakharin Park.

West of the monument of Somdet Phra Sri Nakharin (behind), new trees were planted. Many bricks were unearthed that probably once belonged to this former temple.

The monastery is indicated on Phraya Boran Rachathanin's [PBR] map drafted in 1926 CE, but no traces of it could be found, and as such, I classified the site as defunct.

A 19th-century map indicates the monastery in nearly the same position as PBR does. Historical data about the monastery and its construction are not known.

The site was in geographical coordinates: 14° 20' 37.85" N, 100° 33' 0.11" E.