Wat Thammamun Worawihan

Luang Pho Thammachak is Chai Nat's guardian Buddha: a standing image in the 'restraining the relatives' pose on a five-petal lotus base, about 8 sok (about 4 m) tall, originally bronze but now covered in plaster, with a Dharma wheel in the right palm linked to the marks of a Great Man. Its style blends late Chiang Saen, early Sukhothai and Ayutthaya, and it stands in the vihara on the hillside.

Legend says Luang Pho Thammachak floated down the Chao Phraya and circled in front of the temple; villagers could not haul it ashore with rope and sacred thread. Next day it had moved into the hillside vihara and blocked the doorway, so the villagers extended the vihara to three bays. It vanished again and reappeared in the river, so they chained it. A northern rafter searching for it dreamed it wished to stay and asked only for the wheel in its palm; after that it stayed put, the chains came off and villagers made a new wheel.

The small ordination hall holds a U-Thong-style bronze Buddha that King Rama V had enshrined, — the provincial Buddhism office confirms visits by Rama IV, Rama V, and Rama IX with Queen Sirikit, without dates; Rama V may have stopped during his October 1901 trip north, unconfirmed — and Ayutthaya-style red sandstone boundary stones surround it. Chao Phraya water from in front of the temple is used in the royal oath-of-allegiance rite. A Luang Pho Thammachak coin dated 1918 is linked to the era of Luang Pu Suk of Wat Pak Khlong Makham Thao, and the temple received a royal kathin on 10 November 2007.

About 565 steps, with rest pavilions, climb Khao Thammamun to a shrine of Luang Pho Nak believed to bring success in study and work. The best river views are on the way up and from the temple grounds, as trees block the summit; late afternoon to sunset is best. The temple holds a Luang Pho Thammachak gilding fair twice a year, five days each; in 2026 the sixth-month fair ran about 20–24 April and the eleventh-month fair falls about 30 October–3 November (computed from the lunar calendar — confirm with the temple). By local custom the temple holds Tak Bat Thewo on the 11th waning day of the 11th month — about 6 November in 2026.

It is open about 07:30/08:00–18:00 and free. Cover shoulders and knees and remove shoes indoors. A road climbs to the temple with parking in the grounds. The 565 steps are tiring on hot days, so bring water; they are slippery in the rains, and you may meet mosquitoes, monkeys or dogs. The riverside has flooded in big flood years. Chai Nat Bird Park and Khao Phlong are about 10–12 km away.