A four-day expedition to Tu Lan Cave now costs only VND9 million ($392.44) per person while the three-day journey costs VND5 million, according to major tour operator Oxalis Adventure, the only private company licensed to explore and conduct tours to Tu Lan, En, Va, Nuoc Nut and the world's largest cave Son Doong.

In addition, a two-to-three-day expedition to Tien, En and Va caves are now priced from VND3-5 million per person while a one-day tour to Tien and Tu Lan caves costs only VND990,000.

The discounts only run until July 15 and applicable to intra-provincial travelers amid the complicated development of the pandemic.

Each cave tour organized by Oxalis Adventure is limited to under 10 guests to ensure safety and cave conservation. Each tour is supported by 22 porters, five safety assistants, an international guide, one British cave expert, two cooks and a ranger.

Expensive cave exploration in Quang Binh has been popular among both locals and foreigners. Before the Covid-19 pandemic hit Vietnam in January last year, the prices of tours to these famous caves ranged from VND15-70 million per person.

Nguyen Chau A, CEO of Oxalis, said the unprecedented discounts are part of the tour operator's efforts to survive amid the new Covid-19 outbreak and create income for local tour guides and porters.

He said forthcoming cave tours operated by the company had all been fully booked, but that visitors from others localities were now prohibited from entering the province, meaning these tours had to be canceled.

"These low-priced cave tours would not result in profits, but are the best way to overcome difficulties at this time," he noted.

Oxalis said tours to Son Doong, the world's largest cave, for 2021 have been fully booked and that the cave would be closed to tourists from September until the year-end to allow restoration of its ecosystem.

The number of Vietnamese exploring caves in Quang Binh last year reached record high amid the Covid-19 pandemic, at 6,000, which was three times against the previous years, according to Oxalis.

Quang Binh, home to UNESCO heritage site Phong Nha-Ke Bang National Park, has not yet recorded any community transmissions during the ongoing outbreak that hit the country on April 27.