Locally dubbed as "Wat Yai", the complex is considered the most important temple in Phitsanulok. Housing Thailand's famous Phra Phutthachinnarat, Wat Yai is located at the foot of Naresuan Bridge on the city side of the river. The temple was built during the reign of Phra Maha Thamma Racha I (Phraya Lithai) in 1357.
Phra Phutthachinnarat is considered the most beautiful Buddha image in Thailand.
Other outstanding features of the temple (vihan in Thai) include the large pearl-inlaid wooden doors, the gateway to see Phra Phutthachinnarat. The doors were completed in 1756 by Ayutthaya's royal craftsmen. Inside the vihan are the Italian marble floor, two painted pulpits (thammas) placed to one side, and murals illustrating the life of the Lord Buddha. Apart from Phra Buddha Chinnarat, there are other Buddha images worth seeing. Phra Attharot, a standing Buddha statue cast in same period as Phra Phutthachinnarat, is situated in front of the large Phra Prang (pagoda) behind the Viharn. A 36-metre high Phra Prang was built in the early Ayutthaya style. There are staircases leading up to the place where relic of the Lord Buddha is enshrined.