Dropping into the Gomantong Caves

by James Brickell for Underground Borneo, 21 June 2009

Producer James Brickell enters an extreme cave environment found in one of Borneo's last remaining rainforest reserves. But as he joins presenter Steve Backshall, who is abseiling from the cave roof, he finds that not all wildlife filming is plane abseiling.

I don't think of myself as particularly brave, but I'm comfortable in situations that some people would consider dangerous. I spend a lot of time around venomous snakes, spiders, sharks... Being physically uncomfortable comes with the territory too, but if you want the pleasure of filming animals in the wild it's just what you have to do. But I must confess to one weakness. I am scared of heights. So at several hundred metres deep, the Gomantong caves in Borneo were going to be either a cure or my downfall.

First over the edge

It was as if someone had removed the ground below with a gigantic ice cream scoop.

James Brickell

The rest of the team were all used to heights and Steve is never happier than when he's dangling off a rope staring into some crevasse. I really didn't need to be looking down into a cave. To be honest I could have directed the whole shoot from the car over a radio.

So why, four hours later, I found myself sweating and gasping for breath on the long walk through the jungle to the top of a cave is not entirely clear. Most likely it was the thought of the days, possibly months of teasing I was going to get from the crew, if I didn't join them.

It was decided I would go first, so I started to lower myself over the edge and down towards a ledge, still out of sight.

If you don't like heights you’ll know that some 'edges' are worse than others. The chasm below me was pure terror. Worse even than a sheer vertical drop it actually disappeared as if someone had removed the ground below with a gigantic ice cream scoop.

A swirling mass

I knew I was completely safe but it didn't help. I looked across the chasm to take my mind off things but the swirling mass of millions of swifts and bats made it impossible to focus on anything. It was as if the walls were spinning.

Light streaming from the roof of the caves

At dawn and dusk millions of mostly wrinkle-lipped bats and swiftlets swirl around the caverns. The combined noise is deafening high-pitched drone that sounds like a crowd of mice watching a game of football. Without light they use echolocation to zoom around the caverns without ever colliding or hitting the walls, then they fly into the surrounding forest en masse to wage war on the local insect population.

The most unpleasant place on Earth

Clearly looking down would not be a good plan. I reached one of the support climbers. The terror has since wiped his name from my memory but he was lean, Australian and incredibly patronising. I fought back an urge to hug him, and sob into his shoulder.

"Give it a minute for your hands to stop shaking", he encouraged

"err…I’m not sure my hands are ever going to stop shaking to be honest with you", I felt like I’d done a hundred chin ups.

All the crew who were in the cave for a long time had to don ridiculous looking protective suits.

James Brickell

Several sweat drenched terrifying hours later we found ourselves at the floor of the cave. It may well be the most unpleasant place on Earth. Firstly I was hit by the smell of neat ammonia. It comes from the tonnes of bat droppings that cover the floor and it gets into everything, your clothes, your hair, you can even taste it in your mouth.

It's not just unpleasant, each breath carries the risk of infecting your lungs with a fungus. Untreated it can cause all manner of nasty symptoms including coughing up blood. To prevent this, all the crew who were in the cave for a long time had to don ridiculous looking protective suits and wear simple protective masks. In 40˚C and 100% humidity breathing through one of these things is like being strangled in a sauna.

Mountains of dung

In some places the bat dung is only a metre thick, in others it forms mountains many stories high. The bats add to this festering heap every second so it really isn't a good idea to look up with your mouth open.

It really isn't a good idea to look up with your mouth open.

James Brickell

Feeding on this dung are an incalculable amount of cockroaches. As naturalists of course we all marvelled at how evolution drives life to find a way to exist in this hell hole... but it didn't stop us wanting to squeal in disgust. Even the toughest in the crew couldn't help an occasional yelp as some new horror was illuminated by their head torch. I put my hand out to grasp a handrail narrowly missing a bat, in the process of being eaten alive by a gigantic shining cockroach.

King of Hell

The king of this living hell is a charming creature called a giant Scutigera centipede. The size of a puppy it scuttles around caves, carried along by many pairs of long skeletal legs.

The charming Scutigera centipede

They are highly venomous, one bite and it's off to hospital or worse. In many years of travelling and filming I've never seen anything quite so creepy. In fact the hairs have prickled on the back of my neck as I write this.

When we finally got out of there, we all had our own particular horror moments; the stench, the filth, the animals, but for me that abseil will stay long in my memory. I had thought it might help overcome my fear. It didn’t. And now my fear has a name: the Gomantong Caves.

Closer to home, England's ancient orchards are also home to a group of invertebrates who choose to live amongst the rot. Find out more in The living dead of England's ancient orchards .