Wat Jan, or the Monastery of the Moon (1), is a restored ruin located on the city island in the Ayutthaya Historical Park in the Pratu Chai Sub-district near the Ayutthaya Historical Park Office.

The temple is situated at the corner of Pa Thon Road (Talaeng Kaeng road in earlier times) and Khlong Chakrai Yai, in the Lam Hoei Bridge's vicinity.

Khlong Chakrai Yai is a still existing north-south running canal situated on the Ayutthaya city island. The canal was a shortcut in the oxbow of the old Lopburi River, with its beginning at the Pak Tho Watergate opposite Wat Choeng Tha and its mouth at the Chakrai Yai Watergate in front of Wat Phutthaisawan. The canal and its watergate were named after the Choeng Chakrai Village outside the city wall in that area. [1]

On the opposite side of Khlong Chakrai Yai stood Wat Khok Khamin (defunct), while on its south was Wat Rak (defunct). The Phra Khan shrine and Wat Pa Phai (defunct) stood in the east.

In situ, only some brick foundations of the monastic structure remain.

Engelbert Kaempfer was a medical doctor working for the Dutch VOC (Verenigde Oost-Indische Compagnie) who surveyed the city of Ayutthaya in June 1690 CE. Wat Jan shows on Kaempfer’s map and is marked with a stupa. The monastery is located at the confluence of a minor canal running parallel with Talaeng Kaeng Road (present Pa Thon Road) and Khlong Chakrai Yai, just below the Lam Hoei Bridge.

The monastery is again mentioned on a mid-19th century map by an unknown surveyor and found on Phraya Boran Rachathanin's map drafted in 1926 CE. Phraya Boran was the Superintendent Commissioner of Monthon Ayutthaya from 1925 till 1929 CE. The position of the temple matches both maps.

Wat Jan's historical background and period of construction are unknown.

On the PBR map, the temple is called “Monastery of the Moon” (วัดจันทร์), while on the mid-19th century map it is called “Monastery of the Gold Apple” (วัดจัน) (2).

The site is located in geographical coordinates: 14° 21' 3.31" N, 100° 33' 22.75" E.


(1) The denomination of Phraya Boran Rachathanin on his 1926 CE map has here been followed. (2) Chan (Diospyros Packmanil - C. B. Clarke). A tall tree that bears yellow fruit. When ripe the shape of the fruit resembles the moon. Hence its name. The tree was not usually grown in the house compound, but curiously are to be found in monasteries and the royal palace compounds. If a person dares to plant such trees in his residential compound, misfortune will occur sooner or later to the owner. [2]


[1] Baker, Chris (2011). Before Ayutthaya Fell: Economic Life in an Industrious Society - Markets and Production in the City of Ayutthaya before 1767: Translation and Analysis of Part of the Description of Ayutthaya. Journal of the Siam Society, Vol. 99.

[2] Rajadhon, Anuman (1961). Some Siamese Superstitions about trees and plants. Journal of the Siam Society. Vol 49.1. p. 59.