Wat Yai Chaimongkol, formerly known as Wat Pak Kaeo or Wat Jao Tai, is located in the southeast of Phra Nakhon Island, now part of Klong Suan Phlu Subdistrict, Phra Nakhon Si Ayutthaya District, in Phra Nakhon Si Ayutthaya Province. The temple's highlight is the large chedi, which is believed to have been renovated during the reign of King Naresuan the Great.