So King Naresuan built one on the scene of the singlehanded combat at Nong Sarai in Suphanburi, and a bigger one on the premises of Wat Chao Phyathai. This second chedi built by King Naresuan was named Phra Chedi Chai Mongkol, or Chedi of the Auspicious Victory, and it was popularly known as Phra Chedi Yai, or the Great Pagoda.
So. later on Chao PhyaThai came to be known also as Wat Yai Chai Mongkol. The top of this chedi is visible to visitors from Bangkok as soon as they enter the boundary of Ayutthaya.
(historical notes from documents by the Department of Fine Arts)