This is a heritage of Cham culture reused by the Vietnamese as the capital centre of 03 districts under the reign of King Le Thanh Tong in 1472.

The stronghold, with its wall over 4 m high, the top averagely 5 m and the bottom 25 m wide, the water line in the ditches 40 m wide, found so far as the only earthed fortress by the Cham people that remains today, was believed to be built in 9^-th century in a large area of communes of Tinh Chau, Tinh An, Tinh Thien, Tinh Khe in Son Tinh District, Quang Ngai Province.

The remaining traces show Chau Sa used to be not only a military fortress but also an economic centre in the south of Cham Kingdom.

The whole citadel was surrounded by a system of deep ditches. The inner circle, the central part looked like 02 crab’s pincers running north-south and east-west respectively, connecting the citadel with Tra Khuc river.

Cham people were believed to have been good at water fighting, thus most of their fortresses were found near rivers. And Chau Sa Citadel was connected with Tra Khuc river by a system of ditches navigable for ships and boats. This was considered an ideal defensive shelter.

The outer was in the north-south direction including the two walls in the east-west and north. This used to be a place where pottery production took place. Pottery products of historic value have been so far found through excavations.

And in 1994, Vietnam’s Ministry of Culture and Information did categorize Chau Sa as a National Historical and Cultural Relic.

Perhaps, Chau Sa is a large-scale earthened stronghold which remains most intact among other Cham strongholds in Central Vietnam.

M.T