Just after sunrise swirling mist flows over the track ahead of us. We pause a little further on where a plaque has been fixed to a natural rock wall. The mist wavers from thin and eerie, to thick and impenetrable, and then back again. The plaque commemorates Chris Donnan, an Australian army officer who was last seen here during a climb in 1971. We rest at what is known as saddle camp and I contemplate fate. After ten minutes our party continues on the final ascent.

Mount Wilhelm lies in the Bismarck Range, a range characterised by razorback ridges and steep drops into lowland valleys, which forms part of Papua New Guinea's central chain of mountains. This mountain chain is complex, with broad upland valleys between the numerous ranges. The summit of Mount Wilhelm borders three provinces, Simbu, Madang, and Western Highlands. However, the mountain is best approached from Kundiawa in Simbu Province along the Simbu valley. At an elevation of 4509 metres, Mount Wilhelm is the highest peak in Papua New Guinea. It dwarfs Australia's Mount Kosciusko, is taller than Europe's Matterhorn and nothing higher is found across the Pacific until South America.

Soon after leaving saddle camp we hit patches of snow which became thicker along the trail ahead. We are 650 kilometres from the equator and the steamy coastline around Madang is visible. There is something incongruous about it but also exciting. One for the grandchildren - tropical snow!

Closer to the top the snow is thick on flat surfaces but has trouble gaining a foothold over most of the steeper rocky slopes. The summit is reached in 40 minutes from saddle camp. Our party is lucky - views extend for well over a 100km in all directions. The volcanic mountains of Manam and Karkar are visible off the north coast. To the south, the Gulf of Papua disappears in haze and most of the highland valleys are filled with cloud. A line of pure white cloud joins the lowland Ramu and Markham valleys while the mountains encircling the Wahgi valley resemble a ragged edged container full of soft cotton wool.

One of the more eccentric members of our party has lugged a bottle of champagne to the summit. It is put on ice while we await the stragglers, then uncorked. We toast Papua New Guinea and ourselves. It has been a solid four hour climb from the A-frame hut near the shore of Lake Aunde.

The danger of climbing Mount Wilhelm should not be exaggerated. With a guide and a reasonable level of fitness the climb can be accomplished easily. No technical equipment is required and hands are used only for the final scramble up the rocks to the summit. Climbers should be aware of the dangers of altitude sickness and take the required precautions.

On the ascent, my mind was focused on reaching the summit. However, as we descend, I can more fully appreciate the beautiful environs leading up to the top. During the last ice age, slow moving glaciers carved deep U-shaped valleys around Mount Wilhelm and today four large lakes exist as a legacy to the glaciers. The main base camp is beside Lake Aunde at 3480 metres. We reached this camp in around 3 hours from Keglsugl at the top of the Simbu valley, just below the end of the road from Kundiawa. From the base camp the route traverses around Lake Aunde, climbs 150 metres to Lake Pinde, then heads up to Bogunolto Ridge. The track meanders along and around the ridge until saddle camp is reached.

On the climb back down from Bogunolto Ridge, parts of an aircraft wreck lie beside the track. We had passed them without noticing in the semi darkness on the way up. The point of impact is higher up on the ridge where pieces of aluminium and other wreckage cover a large area. I detour up the ridge while the rest of our party continue on to base camp. From the main impact area, Lake Pinde is just visible hundreds of metres below at the top of the Pindaunde valley. The plane was a F-7 Liberator and had taken off on a photo reconnaissance flight out of Nadzab in May 1944. Eleven crew were killed in the crash. The war touched even very remote parts of PNG.

Further down, the glacial lakes again come into full view and are friendlier in the full morning light than they were in semi darkness. The lakes increase the variety of habitats and add interest to the region, warranting a day or two to explore them. Being tropical alpine, the area is unique. The flora and fauna here is interesting especially in regard to the origins of various plant and animal species. Researchers have determined that although most alpine flora immigrated to New Guinea, some evolved from forest ancestors. This habitat is home to many species of mammal and other animals. Sightings may be made of the Princess Stephanie bird of paradise in the splendid montane forests between Keglsugl and Lake Aunde.

As I approached the safety and security of the hut at Lake Aunde my thoughts wandered back to the climb. My initial feeling upon reaching the summit was one of satisfaction; satisfaction with conquering the mountain. As my pulse rate slowed and the incredible views were taken in, I felt a sensation of sheer admiration and empathy with the mountain environment. A while later, after the champagne, the photos, and rest, the mood changed again. Clouds started rising and the wind slowly became gusty and stronger. Our fragility standing on the top of Papua New Guinea became obvious. We started our retreat, leaving this beautiful but hostile environment.