he move came with bad timing, as Vietnam was in the middle of a campaign to boost tourism, the agency said.

Quang Binh should consider increasing the fees at a different time, and even offering discounts to local tourists, it added.

Early this month local tour operators complained about the province’s doubling ticket prices at the Phong Nha - Ke Bang National Park, which boasts a series of caves that have made global headlines since being discovered by a group of British explorers in 2009.

Entrance to Thien Duong (Paradise), for instance, now costs VND125,000 (US$5.83) for children and VND250,000 ($11.67) for adults, compared to VND60,000-120,000 previously.

Ticket prices to Phong Nha and Tien Son caves have also shot from VND40,000-80,000 to VND80,000-150,000.

The province’s authority claimed that they needed more money to maintain the caves.

By N.Tran Tam - Thanh Nien News - January 30, 2015