English: Wat Yai Chai Mongkhon is situated in Klong Suanplu sub-district, PhraNakorn Si Ayutthaya district. It is presumed that this Buddhist temple was constructed in 1357, in the reign of King U-Thong, on the site where the princesses - Chao Kaew and Chao Thai, were cremated. Later, It was the presence of a priest in the King's Grand Patriarch Sangha and was promoted to a temple named “Wat Chao Phayathai” or “Wat Pa kaew”.

In 1592, King Narasuan expanded the chedi, and also constructed a chedi “Phra Maha Chedi Chai Mongkhon” as a memorial to the defeat of the then Burmese crown prince in the duel on elephant back. It is usually called “Wat Yai” or “Phra Chedi Yai” by most people, and became the tallest chedi in the province until today.

Phra Maha Chedi Chai Mongkhon is a bell-shaped chedi surrounded by small chedis in each corners. There is a King Narasuan palace outside the temple with King Narasuan monument inside, the last sculpture by “Kaimook Chuto” the sculptress of the royal court. The temple was awarded a temple with outstanding development in 1996, and was again recognized as an excellent temple with development in 2000.