Wat Sing Pak Nam or the "Monastery of the Dwell at the Mouth of the River" was located off Ayutthaya's city island in the southeastern area at Ko Rian sub-district. The temple stood on the east bank of the Chao Phraya River and at the mouth of the Suan Phlu canal just opposite the English settlement in an area called Pak Nam Mae Bia (ปากนำแม่เบี้ย).
There are no traces remaining in situ above ground level. Some remains of the temple were excavated by the Fine Arts Department (FAD) in Geo Coord: 14° 20' 15.46" N, 100° 34' 39.23" E (based on 2007 map).
Its historical background and period of construction are unknown.
In the manuscript "Testimony of the king from Wat Pradu Songtham", a document likely compiled in the Early Ratanakosin Period, is written that there was a land market at Wat Sing in front of the Japanese building (1) 
 Khamhaikan khun luang wat pradu songtham: ekkasan jak ho luang [Testimony of the king at Wat Pradu Songtham: documents from the palace]. Edited by Winai Pongsripian. Bangkok: Committee to Edit and Print Thai Historical Documents, Office of the Cabinet, 1991.  Note on the Testimonies and the Description of Ayutthaya - Chris Baker - Journal of the Siam Society, Vol. 99, 2011 - page 77 (paragraph on KWPS).
Text by Tricky Vandenberg - May 2009 Text review & map April 2011, October 2013