Thoongsetthi Ancient Monument was located at Tambon Nayang Cha Am, Phetchaburi Province. The big square Stupa was constructed by brick and mortar, with 25 meters wide and 5 meters high.
There are two staircases on the East and the West that indrocued to the gallery surrounding the main stupa whose base three porticoes in each side. The pinnacle was collapsed. According to evidences we found that the Stupa was ornamented with stucco mounding that showed an images of man, animal and many decorative designs.