During Songkran festival, people will carry sand from riverbank to pile in the ground area in nearly temple. Once the pile of sand is big enough, they will shape it in pagoda style and decorate with colorful papers. In the north of Thailand Lanna people will insert the stem of the traditional flag into the pagoda as well. This is the belief that everyday people go to temple and comeback home after finish their activity, some sand or soil in the temple will stuck on their shoes and this is supposed to be sin as this is not allowed by the monk.