Peter McNab, a construction management student at the University of Abertay Dundee, has travelled to Vietnam to take part in the exploration of the Hang Khe Rhy cave system.

Cave man: The Abertay Dundee student will follow the world's longest river in a cave

The cave, believed to be about 30km long, is to be measured and mapped by Peter McNab to an accuracy of 10 centimetres. This first exploration of the cave system will involve staying continuously underground for at least 10 days.

"It's a part of the world where no one has ever been before. And if no one's ever been there you don't know what you're likely to find."

The cave, situated in the province of Quang Binh, contains what is believed to be the longest river within a cave in the world. Reaching the mouth of the cave will take a day's drive along the Ho Chi Minh trail, followed by an eight-hour walk through deep jungle.

Light falling within the Hang Khe Rhy cave system

Mr McNab, aged 30, is part of a joint British and Vietnamese project to chart the massive cave system.

"Once inside, my role will be to map the cave for posterity, using a compass, global positioning system, tape measure and clinometer," he said.

"We know where the entrance to the cave is and we have located its exit. The distance between these two points is 30km.