Vietnamese folk tradition ranks Tan Vien Son Thanh as the first and most senior of the Tu Bat Tu, the Four Immortals, a set of culture-hero and protector figures also including Thanh Giong, Chu Dong Tu and Lieu Hanh, each addressing a distinct and complementary domain of concern, flood control and settled agriculture in Tan Vien's case, defence against invasion for Thanh Giong, and other themes for the remaining two, together forming something close to a shared moral and cosmological map of what Vietnamese folk religion considers essential for the nation's survival and flourishing. Temples dedicated to Tan Vien Son Thanh cluster around Ba Vi and the wider region historically associated with his cult, and he continues to receive active worship and festival observance today rather than surviving only as a figure of historical legend, situating him within the broader living pattern of Vietnamese ancestor and hero veneration that runs alongside, and often blends with, Vietnamese Buddhism and other imported religious traditions rather than existing as a separate, competing system.