Phra Prang Sam Yot is Lopburi's largest ancient Khmer temple. Its three laterite towers and later Buddhist additions show how the city moved through Khmer, Mahayana and Ayutthaya cultural phases.
The SAC record dates the monument by its laterite construction and stucco style to the late twelfth or early thirteenth century, around the reign of Jayavarman VII. It identifies the temple as an important example of Khmer architecture in Lopburi.
During King Narai's reign, an Ayutthaya-period vihara was added in front of the towers and housed a seated Buddha. The temple therefore records religious change rather than one fixed architectural moment. Follow conservation boundaries around the ancient masonry.