QUẢNG BÌNH — Authorities in central Quảng Bình Province have approved a new expedition route, through the world’s largest cave, Sơn Đoòng.

Following the approval, the sole tour operator to Sơn Đoòng, Oxalis Adventure Tour, will cut short the time visitors spend inside the cave to four days and three nights. This was previously five days and four nights.

Under the old expedition route, visitors had to trek from the front entrance to the end of the cave, and return by the same route to exit the cave from the front entrance gate. However, now, the time spent in the cave will be shortened by one day and one night, by allowing visitors to exit the cave through a gate at the cave’s end, after climbing a stalactite cliff, also referred to as Việt Nam’s great wall.

With this new exit method, Oxalis had to install an aluminum ladder that will assist visitors in climbing. In May, a proposal for the ladder installation had sparked opposition, mainly among Vietnamese net citizens who were not able to comprehend the ladder structure and said the installation would harm the stalactite system.

However, Howard Limbert, an expert in the caving team of the British Cave Research Association that helped discover the cave, reassured the citizens that the ladder would be hammered to the karst surface and would not impact the stalactites.

Limbert said it requires 23 nails to permanently stick onto the karst surface, of which, eight would be installed, while 15 others were hammered by the British association’s explorers in 2010 during an exploration trip.

According to Limbert, the ladder would help to reduce the time trekkers spend in the cave, which meant less human impact on the grotto.

This year’s caving programmes ended in August, before the flooding season as it could pose a danger to the trekkers. A total of 718 visitors were allowed to trek this year.

Oxalis limits the number of visitors to the cave each year, to ensure less damage to the caves. The operator’s sustainable trekking rules are closely monitored by experts of the British Cave Research Association.

Expeditions to the cave will begin early next year. — VNS