Deep, dark and exotic, the very notion of Borneo rouses something in the subconscious. Summoning visions of mythical people and ancient forests, it tugs at the adventurer within. It’s a romantic notion, but the world’s third-largest island has managed to keep some of her secrets and most of them lie in the impenetrable interior of Kalimantan.

Occupying two-thirds of Borneo’s primeval land mass, Kalimantan is one of Indonesia’s least-visited provinces. A void on the tourist radar, it’s a red flag to those hungry for the unknown. Mountains, forests and mighty rivers stretch across the interior, influencing the culture, history and livelihoods of villages throughout. Although the logging and mining industries have had a 30-year feeding frenzy, the fury of the chainsaw and the tide of wasteland is beginning to slow. But you need to be quick – Kalimantan’s hidden world continues to diminish.

The once mysterious Sungai Mahakam is now a highway of river traffic, yet treacherous rapids still protect the customs of traditional Dayak villages. Even the urban jungle begs exploration. Dawn canoe rides to Banjarmasin’s floating markets and dusk journeys through its enigmatic canals imbue travellers with a taste of modern culture.

You can trek in Kayan Mentarang National Park, the Apokayan Highlands, and around the eastern reaches of the vast Sungai Kapuas. And with little effort you can come face to face with orang-utans, macaques, proboscis monkeys, bird life and maybe even the odd sun bear.