this structure contains The Buddha's breast bone, and as such, it is one of the most important Theravada Buddhist structures in the region. It was originally built in the 16th century by the Laotian King Setthathirath of Lanxang. Each year, a festival is held in That Phanom to honor the temple. This festival lasts for one week, during which thousands of people make pilgrimages to honor the shrine.