Layout of the temple was a rectangle. Viharn was home to the Phra Si Sanphet Dayan, the standing Buddha with 16 meters height. The core of the statue made of bronze covered with gold. During the second war, the Buddha was burnt for gold taking by Burmese, leaving only the bronze core. Currently the core is stored inside Phra Maha Chedi Si Sanphet Dayan at Wat Pho, Bangkok.
Behind the viharn, there are three large main chedis contained the bone of three kings. The subordinate chidis are collected other royal member bones. The survey found that the chedi vault was kept a seven-tier miniature chedi with Buddha relics inside.
However, in the era of King Suer, a thunderbolt struck at the tip of the dome which causes damage to the dome. The King ordered to restore the dome and change the roof of the dome to a cathedral and the top of Pra Mongkolborpit was extended during the reign of King Barommakote. During the 2nd fall of Ayuttaya, Viharn Pra Mongkolborpit was ruined by the enemy. After that King Rama 5 ordered to restore this viharn again in the Ayuttaya architectural style. It is a good model of the Buddha image during the end of Ayuttaya reign.