Wat Sri Sawai, in the southwest corner of the central zone, is the oldest structure in the park. Its three corn-cob-shaped prangs were built by the Khmers in the late 12th or early 13th century, when this region was still on the northwestern fringe of the Angkor empire, as a Hindu shrine probably dedicated to Shiva. After the Sukhothai kingdom emerged, the temple was repurposed as a Buddhist sanctuary and given a vihara, viharas and an outer wall.
The combination is unusual and instructive: a Khmer monument in stucco and laterite at the heart of what would become the founding Thai capital, a visible reminder that Sukhothai did not appear in a vacuum but inherited an existing landscape of cities and shrines. Carvings of Hindu deities and the lingam pedestal are still visible inside.