Over three decades ago, a scrap merchant got an "amazingly" high price for a ceramic item he found on the bed of the Huong (Perfume) River in the former imperial city of Hue.
Since then, several divers joined the business of searching for antiques on the riverbed, and many precious items have been found.
Nguyen Van Can and Pham Van Thuan are among these antique seekers, and both of them have over 20 years of experience on the job.
They say the Huong River is over 100km long but the antiques are to be found on a 20km stretch in the lower reaches that run from Long Tho Hill to the Thuan An Estuary.
Different sections of this stretch hold different groups of antiques, they say.
Ancient stones and weapons have been found in front of the well-known Thien Mu Pagoda while the next section – from Kim Long Village to the area in front of the Hue Citadel – has released old bowls and dishes, jewellery and coins.
From the Phu Xuan Bridge to a tributary of the Dong Ba River branch, a section holds a lot of military equipment and weapons from the former US-backed Sai Gon regime.
The section to the south of Hen (Oyster) Islet keeps a lot of mushroom-shaped lime-pots of the former Champa civilisation, while another that runs from the Bai Dau area to the Sinh Crossroads has a lot of Vietnamese Chu Dau, Chinese and Champa ceramic wares of different types.
Researcher Ho Tan Phan, who has a big collection of antiques lifted from the bed of the Huong river, says the "allocation" of different kinds of antiques to different sections of the river is testimony to a "very special" cultural phenomenon in Hue.
He says many more studies need to be carried out to discover and clarify many cultural and historical aspects of the ancient city of Hue in particular and of Viet Nam in general.