STDe said 70 percent of the country's tourism sector focused on Vietnam 's 3,200km coastline.

Over the next 20 years, the STDe said it planned to cash in on the popularity of the sea by developing a tourism industry around salt production.

"Combining salt production with tourism is a way of capitalising on the popularity of the coast," said Nguyen Thu Hanh, STDe's chairperson.

Building salt parks will help promote the industry and preserve a traditional way of life, she added.

Planned parks would have attractions such as salt caves, slides, mazes, art exhibitions, spas – even salt hotels and villages, she said.

Next month, work will start on a pilot salt park in Ha Long, in northern Quang Ninh Province and on Cat Ba island in Hai Phong.

"But to turn the idea into reality, we need every sector of the tourism industry to participate," Hanh said.

Pham Trung Luong, deputy director of the Institute for Tourism Development Research, said the tourism sector had done little to exploit the central province's coastline over the last 10 years.

"The lack of long-term and proper investment in coastal tourism means we have overlooked our region's natural advantages," he said.