This is the oldest wát in Phrae, probably dating from the founding of the city in the 12th or 13th century. There's also a museum here displaying some fine artefacts from the Lanna, Nan, Bago and Mon periods.
The veranda of the main wí·hăhn (sanctuary) is in the classic Luang Prabang–Lan Xang style but has unfortunately been bricked in with laterite. Opposite the front of the wí·hăhn is Pratu Khong, part of the city’s original entrance gate. No longer used as a gate, it now contains a statue of Chao Pu, an early Lanna ruler.
Phra That Luang Chang Kham, the large octagonal Lanna-style chedi, sits on a square base with elephants supporting it on all four sides. As is sometimes seen in Phrae and Nan, the chedi is occasionally swathed in Thai Lü fabric.
The museum displays temple antiques, ceramics and religious art. The 16th-century, Phrae-made sitting Buddha on the 2nd floor is particularly exquisite. There are also some 19th-century photos with English labels on display, including some gruesome shots of a beheading. The museum is usually open weekends only, but the monks will sometimes open it on weekdays on request.