Across the moat from the royal palace ruins, on the north bank of the former Lopburi River channel. This is the most historically significant intact temple in Ayutthaya — it survived the 1767 Burmese sack and gives a direct sense of what the city's religious buildings looked like before the destruction.
The viharn dates from the 16th century, though it was heavily restored in the early 19th. Inside, the principal Buddha sits in royal regalia on a throne-like seat — an Ayutthayan style rarely seen now. A smaller ordination hall behind holds a remarkably fine Dvaravati-period stone Buddha, seated in the European pose with feet flat on the ground, a posture seldom found in Thai Buddhist art. Most visitors to the historical park skip this temple, which makes it a quiet and rewarding alternative to the crowded central ruins.