Mount Kinabalu is a geological infant. Its core is a massive pluton of granodiorite that intruded into older sedimentary and ultrabasic rocks, cooled, and hardened roughly 10 million years ago. In geological terms, that is barely a moment. The mountain's jagged silhouette -- those raw, craggy peaks that look freshly fractured -- reflects this youth. Erosion has not yet had time to round off the edges. During the Pleistocene, about 100,000 years ago, glaciers covered the upper slopes. As the ice sheets flowed downward, they gouged Low's Gully into the mountain's north face -- a ravine 1.6 kilometers deep and 10 kilometers long, named for Hugh Low, the British naturalist who first reached the summit in 1851. Isostatic forces continue to push the mountain upward at roughly five millimeters per year. It is one of the youngest non-volcanic mountains on Earth, and it is not done yet.

The mountain's extreme height creates a biological phenomenon that scientists call a sky island. During glacial periods, cold-adapted species retreated to the summit zone as lowland temperatures shifted. When the ice receded, those populations remained stranded at altitude, isolated from their nearest relatives by thousands of meters of warm, wet forest. Over time, they evolved into species found nowhere else. A 2015 Malaysian-Dutch study confirmed that much of the unique flora, fauna, and fungi on the summit are younger than the mountain itself, having evolved from both local and distant montane ancestors. The results are spectacular: 866 orchid species in 134 genera; multiple species of carnivorous pitcher plants, including the legendary Nepenthes rajah with its bucket-sized traps; and Rafflesia keithii, whose parasitic flower grows up to 80 centimeters in diameter. Among the endemic animals are the Kinabalu giant red leech and the Kinabalu giant earthworm. The rhinoceros hornbill, mountain serpent-eagle, and Dulit frogmouth patrol the canopy.

Climbing Mount Kinabalu is like walking from the equator to the Arctic in two days. The lowland dipterocarp forest, extending to about 1,500 meters, has a closed canopy reaching 40 meters, with emergent trees punching even higher. Above that, montane cloud forest takes over -- the canopy drops and the air turns cool and perpetually damp. Oak, rhododendron, and conifer species dominate here, and the understory fills with orchids and ferns in bewildering variety. Carnivorous plants -- Nepenthes, Drosera, and Utricularia -- reach their greatest diversity between 2,200 and 2,550 meters, thriving where rainfall is heavy and the tree canopy stunted enough to let in light. Above the tree line, alpine meadow gives way to the bare granite of the summit zone, where temperatures range from minus 4 to 8 degrees Celsius in the coolest months. Frost forms regularly at the top. Occasionally, as in 1975, 1993, and 2022, it snows.

Low's Peak can be reached without technical mountaineering equipment by a person in reasonable physical condition, but the ascent is not casual. The summit trail begins at Timpohon, with the Mesilau Trail offering an alternative approach. National park regulations require every climber to be accompanied by an accredited guide at all times -- a rule driven by both conservation and the real risks of altitude sickness at nearly 4,100 meters. Climbers typically spend a night at Laban Rata, the mountain hostel, before beginning the final push to the summit in darkness, timing their arrival for sunrise. The reward is a view that stretches across Borneo to the South China Sea, across cloud layers, across the jagged granite teeth of neighboring peaks. Hugh Low, standing at that same point in 1851, could not have imagined that the peak bearing his name would one day draw tens of thousands of climbers annually to a mountain that the local Kadazan-Dusun people have always regarded as sacred.