Wat Khao San Dam, or the Monastery of the Black Milled Rice, was located off the city island in the northern area of Ayutthaya, in the Hua Ro sub-district. The monastery is on a small island called Ko Loi (1).

The monastery features on 1974, 1993 and 2007 CE Fine Arts Department map. The ruins of Wat Khao San Dam can be found north of the present Ayutthaya Ship Building Industrial and Technology College (Boat School), on which premises are the remains of Wat Inthawat (Wat Sri Jampa). Wat Sri Jampa stood northeast, nearly opposite Wat Khao San Dam, while the bell tower of Wat Saphan Kluea stands, still visible on its west, along the Front Moat.

In situ is a brick mound with a small vihara built on top, featuring the Buddha in a sitting position and bhumisparsa hand gesture or mudra (Buddha calls the Earth to witness his enlightenment) and his two main male disciples Mogallana and Sariputta. When scraping the brick mound, black rice grains can be found.

Some temple remains are in geographical coordinates: 14° 22' 1.86" N, 100° 34' 42.22" E.

Its historical background and period of construction are unknown.

Wat Wat Khao San Dam was one of the six monasteries on Ko Loi. The other temples were: Wat Monthop, Wat Khae, Sri Jampa/ Wat Inthawat, Wat Ngu, and Wat Saphan Kluea.


(1) Ko Loi, or Floating Island, is surrounded in the north by Khlong Chong Lom, in the east by the (new) Pa Sak River and in the west by the (new) Lopburi River. Khlong Chong Lom was dug in the early 20th century to reduce the whirlpools near Wat Tong Pu and the Chantra Kasem Palace, separating Wat Chong Lom from the eastern mainland. As the Lopburi River and the Pa Sak River were joining near Wat Tong Pu, and the erosive force of the two rivers was destroying the embankment in front of the Chantra Kasem Palace, the idea rose to divert the Pa Sak River. The diversion was made shortly after the digging of Khlong Chong Lom. Khlong Sai, a small canal cutting through the eastern mainland from Wat Chong Lom to the present Ayutthaya Ship Building Industrial and Technology College, was widened and deepened. The Pa Sak River, instead of running in front of Wat Tong Pu, changed its course and ran straight from Wat Pa Kho to Wat Phanan Choeng. [1]


[1] Khemnak, Phayao (2010). Wat Monthop (Amphur Phra Nakhon Sri Ayutthaya). Fine Arts Department 3rd Region. p. 22.