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. The large Sukhothai-style bronze statue was cast in 1357 by the order of King Maha Thamma Racha I of Sukhothai. The statue’s unique feature is the flame-like halo – a symbol of spiritual radiance. In 1931, King Ekatotsarot (King Naresuan’s younger brother) commanded a gold coating of the image, making it outstanding against the dark backdrop.

Today, thousands of visitors, both Thais and foreigners, flock to Wat Yai just to get a glimpse of Phra Phutthachinnarat. Most of contemporary Buddha images are cast using Phra Phutthachinnarat as a model. There is even a saying that, your trip to Phitsanulok is not complete without visiting Wat Yai to pay respect to Phra Phutthachinnarat. Only the Emerald Buddha situated in the Grand Palace, Bangkok, is more highly respected by Thais. A celebration to honour the statue is held annually in late January.

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 thammas (pulpits) placed to one side, and murals illustrating the life of the Lord Buddha.

Apart from Phra Buddha Chinnarat, there are other Buddha imaes 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.

There is also a small museum, which exhibits a good collection of Sukhothai and Ayutthaya-era Buddha images and related religious items that is worth visiting. Visitors are advised to dress conservatively.