The principal prang of Wat Maha That was constructed of laterite at the base. The top
part of the stupa was of brick and mortar. Brick work at the four sides of the base
indicates that the prang had porches in the cardinal directions, a feature not used in the
Early Ayutthaya period (1351 - 1491). These porches could be reached by a staircase.
Historians believe that these porches were added during the renovation of the temple
done in 1633 during King Prasat Thong’s reign. Mural paintings of Buddhas in the
different postures were found inside the prang. The prang stood until the beginning of the
20th century, but finally the brick part collapsed as unfortunately no preserving had been
done since the fall of the city in 1767. Fifty years after its collapse a crypt was found
containing relics of the Buddha inside the stupa.