Wat Phra Si Sanphet was the royal temple inside Ayutthaya's palace grounds. Its three large chedis remain one of the clearest signatures of the old capital.
The temple stood within the royal palace area and served the court. The Fine Arts Department's cultural record dates the viharn and the Phra Si Sanphet image to the reign of King Ramathibodi II, while noting that royal chronicles give different construction dates.
The surviving chedis held the ashes of Ayutthaya kings and form the visual centre of the ruin. The original great Buddha image was lost when Ayutthaya fell in 1767. The Fine Arts Department now maintains the historical park, so stay on paths and do not climb the restored structures.