Track wild orangutans through primary rainforest and cruise the Kinabatangan River at dawn for proboscis monkeys, hornbills and pygmy elephants.
Sabah holds some of the last stands of ancient lowland rainforest in Borneo, and this trip is built to get you into them properly. At the Sepilok Rehabilitation Centre you watch rescued orangutans work their way back to the wild canopy; from there, days shift to the Kinabatangan River, where a slow boat at dawn and dusk drifts past troops of proboscis monkeys, silvered langurs, hornbills and — with real luck — a herd of Borneo pygmy elephants moving along the bank. In Danum Valley, one of the world's most intact tracts of primary dipterocarp forest, guided night walks turn up civets, tarsiers and slow lorises that never show themselves in daylight.
This is a wildlife-first itinerary paced around animal activity rather than sightseeing hours — early starts, quiet boats, and guides who know which fruiting tree to watch. Accommodation ranges from a jungle lodge to a river-camp with open-sided common areas, so nights come with a soundtrack of cicadas and, if you're fortunate, a distant orangutan call.