The Thai Vi Temple Festival is held annually to commemorate the merits of the Tran kings and national heroes, especially King Tran Thai Tong, who made significant contributions by encouraging people to settle and develop the area in Ninh Hai Commune.

According to historical records, after the victory in the first resistance war against the Mongol invaders, King Tran Thai Tong abdicated the throne in favor of his son, Crown Prince Hoang (later Emperor Tran Thanh Tong), and returned to the Truong Yen mountainous region to lead a religious life. There, he transformed the wild forest into a populated area, attracting settlers and founding Van Lam village. King Tran Thai Tong's contributions were immense. After his death at the age of 60 (1218–1277), the people built a temple to worship him, Empress Hien Tu (Queen Thuan Thien), and King Tran Thanh Tong. The temple is called Thai Vi because it is the place where the Tran emperor became a monk. Due to its historical and cultural significance, Thai Vi Temple was recognized as a Special National Historical and Cultural Relic in 1994.

A highlight of the Thai Vi Temple Festival is the preservation and transmission of cultural identity through solemn and sacred traditional rituals such as: the opening of the temple, the palanquin procession, incense offering, traditional ceremonial rites, and thanksgiving rituals. These ceremonies express gratitude to the ancestors and pioneers who reclaimed and developed the land and villages. The rituals reflect the Vietnamese cultural philosophy of “When drinking water, remember its source,” contributing to the preservation and promotion of the nation's traditional cultural values.

The festival also features a lively, joyful atmosphere with the participation of locals and visitors through various traditional folk games and activities such as: boat racing, tug of war, Chinese chess, and to tom diem (a traditional card game).

The Thai Vi Temple Festival reflects a long-standing cultural and historical tradition, preserving ancient rituals of ancestor worship and honoring national heroes. It embodies the Vietnamese moral tradition of remembering and showing gratitude to those who contributed to the village, the community, and the country. Customs such as the Saint procession, palanquin parades, and ceremonial offerings have been maintained and preserved through generations by the people of Ninh Hai Commune.

The Thai Vi Temple Festival is one of the most significant cultural events in the spiritual life of the local people. It serves as a valuable historical document, enriching the diversity of Vietnam’s festival system. It also plays an educational role in passing down local cultural traditions to future generations, wherever they may live, encouraging them to honor their roots and continue preserving their homeland's heritage.