Citadel of the Ho Dynasty” or “Ho Citadel” (in short writing) is a citadel built by stone that stands on a basin between the Ma and the Buoi rivers. The historical monument is belonged and under administrative care of the hamlets Tay Giai, Xuan Giai (Vinh Tien commune) and Dong Mon (Vinh Long commune), Vinh Loc district, Thanh Hoa province, Vietnam.

Throughout its history, the citadel was renamed several times. For example, it was called “An Ton Citadel” during the late Tran period; when it became the capital of the Dai Viet state (from 1397 to 1400); “Tay Do” or the Western Capital. And it was then renamed as Dai Ngu (from 1400 to 1407) during Ho dynasty. When the Ming China occupied Vietnam, it was named as “Thanh Hoa Thanh Phu”. Other names were also used, such as “Tay Kinh” or “the Western imperial citadel” was used to differentiate it from the Thang Long citadel (Dong Kinh or Eastern citadel), “Thach Thanh” or ‘Stone citadel”, because it was constructed by stone, “Tay Giai Citadel”, because it is located adjacent to the Tay Giai hamlet.

If going from Hanoi, first one goes to Thanh Hoa city on the national highway 1A (150km), then one takes the provincial highway No.45 from Thanh Hoa to get there (45km). One also can go there by boat from the South China Sea up to the Len or Ma rivers to the mountainous districts of of Quan Hoa and Ba Thuoc.

Historically, in 1397, Ho Quy Ly, the Prime-minister of Tran dynasty ordered to construct the Ho Citadel. In the same year, he moved the royal court from Thang Long (current day Ha Noi) to the Ho Citadel in
Thanh Hoa.

In 1400, Ho Quy Ly dethroned the last King of the Tran dynasty, and established his own dynasty. He used the newly build capital as his official Imperial Citadel and named his kingdom “Dai Ngu”. In 1407, the Ming China attacked the Ho Citadel, arrested Ho Quy Ly and his son Ho Han Thuong. The Ho dynasty was short lived and the whole royal was collapsed. As a result, the Ho Citadel was no city capital any more.

The heritage site includes monuments that are well planned. It is exceptional because of the way in which the constructed components are harmoniously integrated into the natural environment and adapted to the topography, to serve as a new capital when it was moved from Thang Long (Hanoi). Today, the stone built citadel survives with its massive wall and four main gates. The remaining structure and several components of the citadel were unearthed by archaeological investigation. In addition to the surrounded stone walls, moats, vestigates of palaces and shrines of the royal, Outer wall and the Nam Giao Altar are parts of the heritage complex.