Xen Muong, also known as the “cau mua” (praying for bumper crops) festival of the Thai ethnic group, is held in the third lunar month every year to thank those who contributed to the establishment of the hamlets and the Muong regions; and pray for favourable weather and good crops.

The ceremonial part was held at Lac Man Temple – a provincial historical and cultural relic site which includes Ong Temple and Ba Temple – in Sop Cop hamlet. On the first day, the "Cung ty" (invitation) ceremony was held at Ba Temple, where the villagers prepared offerings, including pigs and sticky rice, while the “Lac man” worship ritual took place on the second day at Ong Temple. The offerings include a tray of food and a buffalo as a sacrifice to pray for the gods to bless the hamlets with peace, good health, prosperity, and bumper crops. During the day, the villagers abstained from carrying things on their shoulders, digging the ground, cutting trees, chopping firewood, and entering the forest.

After completing the ceremonial part, the festive part took place, with such competitions as blindfolded duck catching, blindfolded drum beating, and fish catching. Each competition had 15 teams from the commune’s hamlets, agencies, and units, drawing a large number of people and tourists. At the end of the festival, people and tourists participated in throwing ‘con’ (cloth ball), drinking ‘can’ (bamboo tube) wine, and xoe dance.

The Xen Muong Festival is a traditional ritual in the cultural life of the Thai ethnic group in Sop Cop commune, aiming to promote the value of the historical and cultural relic site of Lac Man Temple. It also helps encourage people to unite, promote production, and build a cultural life in residential areas.