Wat Si Ratcha, or the Monastery of the Glorious King, was located on the city island in the western area of Ayutthaya in the Pratu Chai Sub-district. The site is part of the Ayutthaya Historical Park.

The site shows only on a 19th-century map and does not feature on Phraya Boran Ratchathanin's (PBR) map drafted in 1926 CE, which indicates only empty space in that area. The site is also not found on the Fine Arts Department maps.

The monastery was situated on the south bank of a canal longing Lao Road (Pa Thon Road at present). In the west stood Wat Takhe (defunct), while on its east stood Wat Khok Khamin (defunct).

The monastery showed on Kaempfer’s map and stood on the bank of a canal branching off from Khlong Chakrai Yai. 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. The temple was accessed via Lao Road by a bridge over a minor canal. Kaempfer counted 200 paces (about 150 metres) from the Lam Hoei Bridge towards the temple bridge.

There are no traces visible of the monastery above ground level. I presume this area was already cleared before Phraya Boran Ratchathanin arrived in Ayutthaya. Monthon Ayutthaya had been Phraya Boran's home for 33 years (1896-1929 CE), and he was the Superintendent Commissioner of Monthon Ayutthaya from 1925 till 1929 CE.

Historical data about the monastery and its construction are unknown.

Wat Si Ratcha must have been approximately located in geographical coordinates: 14° 21' 3.02" N, 100° 33' 15.98" E.