THOUSANDS of tourists scale Malaysia's highest mountain every year, but few dare even glance over the edge into the darkness of Low's Gully. As testimony to the danger, two Sarawak climbers disappeared near here in 1988. Despite a month-long search, park officials did not find either body. From the overnight camp atop Mount Kinabalu at 3,350 metres, it is another 760 metres to the peak, then a dizzying sheer drop into the mysterious Low's Gully. The local name for the mountain camp is Panar Laban, meaning Place of Sacrifice. As five Hong Kong and British men who survived the climb wait to see whether Aki Nabalu, or the Place of the Dead, has claimed the lives of five colleagues, the world's top authority on this challenging climb has questioned the planning and wisdom of theexpedition. Until half of the team stumbled to safety after two weeks on the mountain, there had only been one previous expedition through this valley. Stephen Pinfield, a founder of the Outward Bound programme in Sabah, has climbed down Low's Gully not once, but three times. ''Years of planning went into the climb,'' he told the Sunday Morning Post, describing hidden dangers, waterfalls and likely death for anyone trapped in the gully for two weeks. ''When I heard that a group of 10 had gone down there, I thought that was crazy. It's really an unusual challenge. The secret is moving fast. With a big group, the chance of something going wrong just multiplies.'' Mr Pinfield, 40, held out little hope for the survival of the missing men. He believed they had either already perished, or become trapped among sheer rock faces at 2,000 metres. ''Even if they survived a fall or decided to camp and wait for help, they would be weak, cold and without any way of escaping the rain.'' At that height, he added, there was no source of food and little chance of shelter among the barren and slippery boulders, some the size of houses. Mr Pinfield said many British and Hong Kong army groups had explored the area around Mount Kinabalu. ''It's really a bit controversial,'' he said. ''They would come out gung-ho, but blind about the terrain.'' Mr Pinfield, who claimed 15 years of serious climbing experience before moving to Sabah in 1986, now lives in England. He made two exploratory descents down the sheer rock faces of Low's Gully in the late 1980s. Both times, he and his companions went by rope, stayed a few hours to survey the bleak terrain, then climbed out again. ''The bottom of the gully is really a horrible place,'' he said. The sheer face of the slopes end in a stream about 1,200 metres from the peak. Following the stream means climbing under and over huge boulders. Nobody had done it until Mr Pinfield and fellow Sabah-based Briton Robert New in 1991. ''The commitment was the hardest part,'' he recalled. ''At first, we went back up the way we came in, but then decided to really go for it. That meant pulling our ropes down and plunging into the unknown.'' The two-man team prepared meticulously for the trip. They travelled light, carrying only enough food for a week. The key to success, Mr Pinfield said, was the weather. ''We had to be patient and watch the weather patterns, looking for a long clear spell,'' he said. ''Weather is your worst enemy. When it rains, you're doomed. The rocks are slippery and you cannot find a safe place to sleep.'' Rains also turn the route's worst danger into a near-certain death trap, he added. After reaching the stream on the gully floor, Mr Pinfield and Mr New spent two days slowly clambering over boulders during a rapid descent of another 600 metres. Suddenly,the stream ended in two pools surrounded by sheer cliffs. ''Here is the treacherous part. You have to decide whether to swim across with all your gear or climb all the way back up and around. We traversed the cliffs. If we hadn't, we would have been swept to our death.'' The pools flow around a bend in the rock, invisible to anyone standing at stream level, then explode into a 150-metre waterfall crashing down sheer walls of granite. ''Nobody could survive that drop,'' Mr Pinfield said. Worse, he said, with any rain, the two ponds merge into a single surging tide that would sweep any climber to death in an instant. ''Once you're in the pools, you're finished,'' he said. ''And that's in the dry season.'' Some of the Hong Kong and British climbers who survived, lost their packs, including camera equipment and supplies, in horrendous falls. But once past this perilous point, the rest of the descent was routine, he said. In the jungle below, people familiar with survival techniques could easily subsist on wild fruit, greenery and game that included boars, mouse deer and rodents. However, Mr Pinfield discounted speculation the climbers were lost in the jungle. ''Even if one or two of them were hurt, someone could go ahead for help. Once you reach the valley floor, you'd be to safety within two days at the most.'' More likely, the climbers had become trapped hundreds of metres up the gully, either by the perilous mountain pools, or higher. As rescue efforts continue, Mr Pinfield also worried about the danger to the rescue team. ''All those people going down in the gully is risky,'' he said. ''And even if you find them, getting them out is another matter. The danger level multiplies every time someone else goes down there.'' The expedition could become the biggest tragedy ever in Sabah Park, a 70,000-hectare reserve around Mount Kinabalu established in 1964. Francis Liew, deputy director of the park, said only three people had died there in the past 20 years. The park is extremely strict about safety. All climbers must register at the park office and pay for a professional guide service on the mountain. Over 200,000 visitors come to the park annually.