Glimpse within: View inside Son Doong, the world's biggest cave. — Photo courtesy of Adam Spillane

QUANG BINH — Authorities in central Quang Binh Province have given the go ahead for a highly controversial cable car system connecting various sites in the Phong Nha-Ke Bang National Park to the world's biggest cave, Son Doong.

However, they promised to carry out the work with "tight consultation" from UNESCO and related agencies.

Son Doong, which has been extensively explored by British Cave Research Association, has attracted enormous interest for its beauty and pristine conditions.

Province chairman Nguyen Huu Hoai, who chaired a press meeting addressing the issue on Tuesday, said the cable system was needed to boost local tourism as the province was among the poorest in the country.

A gate of Son Doong Cave. — Photo Adam Spillane

He said authorities were aware of possible damage to the weak topography in the area around the cave. Scientists have warned that any construction impacts could lead to collapse of the cave.

However, Hoai failed to explain how to ensure the safety of the cave from this threat. Also attending the meeting, Le Thanh Tinh, director of the Phong Nha-Ke Bang National Park, admitted that large forest trees would be logged to provide poles for the cable system.

The park is "fully protected" under Vietnamese Environmental Law, and no construction or development can be done without permission.

Inside the Son Doong Cave. — Photo Adam Spillane

The park is a UNESCO heritage site and under the management of the Ministry of Agriculture and Rural Development.

Meanwhile, a surge of opposition to the project has arisen around the world and on online forums.

Scientists, environmental activists, locals and others demand that the cave be left alone to preserve its fragile beauty.

There is an online petition at www.thepetitionsite.com/takeaction/956/103/062/ calling for signatures to stop the projec