Wat Prasat or the "Monastery of the Palace" was located on the city island in the northeastern area at Ho Rattanachai sub-district. It was situated south of Wat Khwang and on the north bank of Khlong Pratu Ho Rattanachai near the Ho Rattanachai Gate.
The temple area has a classical outfit, quite large and well kept. Each of the monastic buildings has its proper inner wall and is beautiful decorated. The ordination hall has a three-tired roof, while the main viharn has a two-tiered one. The latter contains a Buddha image of Wat Khwang, a former monastery north of this temple.
Its historical background and period of construction are unknown.
Hengpujaroen wrote that according to some old documents, the walls around the Chan Kasem Palace or Front Palace had a length of 50 Sen (1) or approximately 2000 m. The palace occupied thus an area roughly going from the Unmilled Rice Fort (Pom Khao Phluak) and Wat Tha Sai towards the Maha Chai Fort; going down to the Ho Ratana Chai Gate and running back along the Ho Ratana Chai canal towards the Unmilled Rice Gate. The palace area should have included at least eight monasteries, which one of them was Wat Prasat. The issue of a such large palace ground as mentioned here, was although heavily discussed by scholars and rejected.