Travel: The truth about Birds Spit Soup

Swallows who make edible nests are not the strangest thing in Sabah in Borneo. There are the Wild Men, for a start.

Now I know that travel writers usually describe the places they visit in loving prose, so that the destination glows off the page, but I just have to tell you about the most disgusting place I've ever visited; the Birds Spit Soup caves of Gomantong.

Perhaps it was an effect of contrast. I was in Sabah in Borneo, the third largest island in the world and certainly one of the most beautiful. It lies in the South China Sea a few hundred miles east of Singapore. I had wanted to go there after reading Joseph Conrad's stories; I had pictures in my mind of steamy jungles and sparkling seas dotted with tropical islands. These impressions were all confirmed.

Travel: The truth about Birds Spit Soup

The southern half of Borneo now belongs to Indonesia and the northern half to Malaysia, split into two regions, Sarawak and Sabah. Bizarrely, Sabah once belonged to an Englishman, the publisher Alfred Dent, who leased it and eventually called it British North Borneo. There was a reminder of the embarrassing ways of the British Empire in the yacht club at Sandakan. One member, a Malaysian Chinese, jerked his thumb at the faded portraits of English club commodores lining the teak walls. The dates were of the early Fifties. "In those days the yacht club members didn't allow the Chinaman on the premises." The implication was obvious: he was showing me a welcome that my countrymen had not shown to his.

There are bleaker Imperial memories in Sandakan. The Japanese established a prisoner of war camp here during the Second World War, and 2,400 Allied prisoners were interned. Survivors were forced to march through dripping jungle for 150 miles, and those who could not walk any further were killed where they lay on the ground. At the end, only six escapees remained alive.

There is little to see of the POW camp today; the jungle quickly erases history.

A kindly sailor took us out to the turtle island of Pulau Selingan in his huge powerboat. We were touching 50 knots as we flashed past dozens of curious wooden structures standing in the shallow sea like rustic oil rigs. On top of each was a thatched hut. In the evening lanterns are lowered to attract fish, which are then netted out. There was a powerful fishy stench as we passed each one.

That starlit night we crouched on the island's beach and watched as a huge green turtle dropped 100 eggs into a pit she had dug in the sand. Soon 3-inch versions of their mother would be making a perilous journey down to the warm, dark sea.

I had vague memories from my childhood of the Wild Man of Borneo - the orang-utan. We went to see him at Sepilok, a rehabilitation unit that aims to make the inhabitants more wild, not less wild, so they may be returned to forest life. The gentle creatures would approach the feeding platform by swinging along ropes slung between the trees and then grab a rotten banana from the heap. Hanging by extraordinarily pink, hand-like feet, they would thoughtfully suck the fruit while gazing upside-down at the hooting, jabbering primates behind the fence.

Further inland we went to another, larger reserve that many people in the UK will have heard of: Mount Kinabalu. A few years ago a British Army team got famously stuck in Low's Gully, a nearly impassable jungle- filled slash down one side of the mountain. I say "nearly" because a group of climbers from Sheffield recently evened up the score by making the first ever traverse through it. The mountain stands in thick rainforest filled with spectacular plants; there are 1,000 species of orchid and the world's biggest flower, the 2-foot-wide red blossom of the rafflesia - named after the founder of Singapore.

If you decide to do the two-day trek up Mount Kinabalu you can soak away your aches in the Poring Hot Springs, a more welcome Japanese invention during the war. You could then stay in the delightfully named Poring Hostel for about pounds 2 a night.

Birds Spit Soup makes its appearance in one of the Doctor Dolittle stories, and I had always been fascinated by the idea. The swallows build their nests in limestone caves at Gomantong, about 12 miles from Sandakan. As you approach you pass the wooden huts of the nest collectors, who gather them with long, shaky wooden ladders and lots of courage. The incentive is money - about pounds 2,000 per kilo of nest.

As we entered the cathedral-sized cavern we were struck by an acrid stench. As our eyes adjusted to the darkness we realised that it was filled with a million wings; swallows, bats and insects. I swung a torch down and saw that I was wading ankle-deep in guano. I looked closer and I realised that the stuff was seething with life.

Insects of all kinds crawled in a loathsome manner across the floor. As we penetrated further, cockroaches crunched underfoot. At least six separate phobias were catered for in this noisome place.

As I staggered out into the sunlight I found that I was liberally bespattered with birdshit - in my hair, on my feet, on my clothes. Looking up into the trees my eyes met those of a orang-utan, the only one I'd seen outside a park. For a moment we both seemed to be wondering which one of us was the Wild Man of Borneo.

Proof of the Pudding

THE NESTS are made by swallows of the genus Collocali. What makes them remarkable is that the birds line them with saliva and pre-digested seaweed, which hardens to a translucent layer. There are many grades; the whiter, and the fewer feathers, the better. I bought two biscuit-sized pieces in the shape of hearts (they are an alleged aphrodisiac) for about pounds 15. They look a bit like nest, but there is no smell and little taste, their function being to provide texture to the soup. Simmered for three hours it tastes a bit like woven gelatin, or a well boiled loofah.