The area is a complex consisting of several temples dedicated to the cult of Hùng Vương – the first descendants the mythological founders of the Vietnamese, Lạc Long Quân and Âu Cơ. Styled sequentially as Hung Vuong I to Hung Vuong XVIII, the monarchs were the first dynastic rulers of Van Lang, the primordial kingdom of the Vietnamese.
Popular belief designates the Hùng temple as also the site of Van Lang's capital, Phong Châu. The kingdom is associated with the Đông Sơn culture and the famous bronze drums. For the successive Vietnamese dynasties and states, the Hùng Temples are revered with annual processional festivities known as Giỗ Tổ Hùng Vương held every 10th day of 3rd lunar month.
According to VietKings (Kyluc.vn)