The Phra Mahathat Chedi Phakdee Prakasan, also known as Wat Khao Thongchai, is a large stupa that was named by His Majesty the King. This structure represents Thai architecture from the Rattanakosin period and was built out of the people’s devotion to the monarchy, without using government funds. It was constructed to honor and dedicate merit on the occasion of the King's 50th anniversary of reign. The stupa's design is bell-shaped, standing on a square base, with its elements symbolizing the significance of the 50-year reign. It consists of five tiers, representing the five aggregates (khandha), while the complex itself comprises nine chedis, symbolizing the official temples dedicated to the Ninth Reign.