The Hung King's Temple is located on Nghia Linh Mountain, Hy Lang Commune, Phong Chau District, Phu Tho Province, 85 kilometers northwest of Hanoi. Every year, a national festival called Hung King's Temple Festival is held to worship the Hung Kings, who were instrumental in the founding of the nation.
The festival lasts for 3 days from the 9th to the 11th of the 3rd month of the lunar calendar. A day before the festival, ancient and modern flags are to be hung along the road leading from Viet Tri to Hung mountain. A large ballon will also publicise the festival to surrounding areas. On the eve of the festival, 100 flying lights are released into the night sky. The main worship service is held in earnest the following morning, 10th day, beginning with a flower ceremony. In Den Thuong (Upper Temple) where the Hung Kings used to worship deities with full rituals, the ceremony consists of a lavish five-fruit feast. Banh chung (square cake) and banh giay (circle cake) are also served to remind people of the Lang Lieu Legend (the 18th Hung King who invented these cakes), and the merit of the Hung Kings who taught people to grow rice.
Next to the stage procession for deities, there are several marches in the procession such as the elephant march followed by the procession chair. These procession marches are conducted in Tien Cuong, Hy Cuong, Phuong Giao, and Co Tich villages. The procession marches are followed by a Xoan song performance (a classical type of song) in the Den Thuong, a "Ca Tru" (a kind of classical opera) in Den Ha (Lower Temple), and other activities like cross-bow shooting, rice cooking, swinging contests, cock fighting, and dragon dancing. Later on this day, a march of local people, including representatives of the country's 54 ethnic minorities will be rounded off with a speech and the release of doves, carrying the hope for peace of Vietnamese people .
The Hung King's Temple Festival not only attracts visitors from everywhere and allows visitors to participate in the special traditional cultural activities, but it is also a sacred pilgrimage back to the origins of the Vietnamese culture. People usually show their love and pride of their homeland and ancestral land. During the festival, pilgrims always spend time visiting the temples and historic sites on Hung mountain. The Den Ha, memorial temple for the primal mother Au Co, is approximately 100 steps higher up, in a countryard entered through a gate with a bell tower. The mother of the Hung Emperors and all Vietnamese is represented on the main altar ; the left-hand altar is dedicated to the last Hung Emperor. The steps continue to the Den Trung (Middle Temple), the main temple, which dates from the 19th century. It is dedicated to the founder of the dynasty and all other Hung Emperors. On the summit of the wooded hill is the Den Thuong, which is dedicated to the gods of heaven and earth. Lying on the middle altar is the sword of Phu Dong, the country's first hero; another altar is dedicated to the wives and daughters of the Hung Emperors. On the hill is a mausoleum for the dynasty. Upon the Stone of Oaths here An Duong Vuong, founder of the realm of Au Lac, who came from the hills to the plain, swore to defend the land of his farthers.
The Hung King's Temple Festival is one of the most important and sacred festivals of the Vietnamese people, deeply imbedded in the minds of every Vietnamese citizen, regardless of where they originate from.