HANOI: A huge residential complex being built on the borders of Vietnam’s Ha Long Bay prompted a public outcry in the Southeast Asian country Monday, as concerns mount over human impacts that have degraded the UNESCO World Heritage Site.

The bay, famed for its brilliant turquoise waters dotted with towering rainforest-topped limestone islands, is one of Vietnam’s most popular tourist destinations, attracting more than seven million visitors last year.

The shore and the surrounding town are already heavily developed. But on Sunday pictures were published in state media of an enormous construction site running through the waters -- and next to the spectacular karsts -- of Bai Tu Long Bay, which borders Ha Long.

The project owner, Do Gia Capital Limited Company, is preparing the ground for a residential and hotel complex on an area of more than 318,000 square meters, Tien Phong newspaper said.

The paper reported that the construction site is in Ha Long Bay’s ‘buffer zone’, which UNESCO says provides an additional layer of protection to a World Heritage property.

Once finished, the complex will consist of 451 villas and houses, multiple seven-storey hotels, and service and trade areas, Tien Phong added.

Truong Quoc Binh, former deputy head of the culture ministry’s heritage department, said “the boundaries of Ha Long Bay had been seriously violated”, according to the paper.

In Facebook posts that received thousands of likes and shares, Nguyen Xuan Dien, a well-known historical researcher, called the plans “a direct threat” to the world heritage site.

“The limestone karsts have been turned into toys of the newly rich”, Dien wrote.

Trang Nguyen, a prominent conservationist, wrote on Facebook: “Killing birds, killing animals, killing everything.

“The mountains are turned into cheap amusement parks, painted with green and red. The sea and its sand is exploited. Beautiful places are auctioned off.”

In response to the criticism, authorities in northern Quang Ninh province -- where the construction site is situated -- ordered Monday an immediate review of the project. The plans received official approval in 2021.

The rapid growth of Ha Long City -- which is now home to a cable car, amusement park, luxury hotels and thousands of new homes -- has severely damaged the bay’s ecosystem.

Conservationists estimate there were originally around 234 types of coral in the bay -- now the number is around half. There is also a huge problem with both human and plastic waste.

UNESCO’s Vietnam office and the Ha Long Bay management board did not immediately respond to requests for comment from AFP.

State media have recently reported on several other construction projects threatening protected areas across Vietnam. -AFP