Wat Saiya (or Chaiya = Victory?) was located on the city island in the southwestern area in Pratu Chai sub-district. It was situated in the present Somdet Phra Nakharin Park; the latter being part of the Ayutthaya Historical Park. The site of the former monastery is accessible via U-Thong road.
The monastery belonged to a cluster of temples located along a canal, connecting Wat Luang Chi Krut with Wat Chao Prab, running parallel with the city’s defense wall.
This cluster of temples was located in a residential area in the reign of King Chakkraphat (r. 1548-1569) also called the "Lord of the White Elephants". Thianracha (Chakkraphat), before ascending the throne, had his princely residence in the area. The area was before important, as most of the palace officials and high ranked persons were living on both sides of the Chao Phraya River between Wat Phutthai Sawan and Wat Chai Wathanaram.
The last traces above ground level of this temple probably disappeared when the Somdet Phra Sri Nakarin Park was constructed. Only a large grass field remains.
Its historical background and exact period of construction are not known, although it is very likely that the former monastery was built in the Middle Ayutthaya period.