Wat Sema, or the Monastery of the Boundary Stone, was located off the city island in the eastern area of Ayutthaya, in the Phai Ling Sub-district. The temple is in the vicinity of Wat Yai Chai Mongkhon, just outside the boundary of the Ayutthaya Provincial Sports Complex.
Wat Fai Mai (defunct) stood north, Wat Maha Thalai (restored ruin) south and Wat Maklam (restored ruin) southwest.
The last traces of Wat Sema are close to disappearing. Only a tiny part of the wall is remaining, next to a small commemoration vihara, while a part of the foundation of a chedi is situated a few meters to the east, on private property.
Historical data about this monastery and its construction are not known however, the Fine Arts Department lists other temples in this area as from the middle Ayutthaya period (1488-1629 CE).
The monastery is indicated on 1993 and 2007 CE Fine Arts Department maps.
The site is in geographical coordinates: 14° 20' 59.56" N, 100° 35' 55.47" E.
(View of the remnant of Wat Sema)
