Wat Tamnak or the "Monastery of the Royal Residence" was situated south of the city island, west of Khlong Khu Cham and south of the Chao Phraya River in Pak Kran sub-district. It was situated just south of Wat Phutthai Sawan.
Except some traces of shattered bricks nothing of the structure remains at ground level. Presently there are houses built in situ. Its historical background and period of construction are unknown.
It has probably a link with the site called Wat Sra Si Liam and could even be related to Wat Phutthai Sawan. As the translation of the word "Tamnak" literally states, the area could have been a kind of Royal Residence for the Ayutthayan Kings visiting Wat Phutthai Sawan.