The Mahakam is one of the great river journeys of Southeast Asia, and Samarinda is where it begins. The river runs about 920 kilometres from its headwaters in the central Borneo highlands to the sea, and the stretch accessible from Samarinda by boat covers several distinct ecological and cultural zones.
The first 45 kilometres to Tenggarong pass through oil palm and coal country, but after that the river starts to open up. Lake Jempang, about 250 kilometres from Samarinda, is surrounded by Dayak villages and hosts freshwater dolphin populations. Further upstream, the Benua Dayak and Benuaq communities live in longhouses that are genuinely inhabited rather than reconstructed. Melak, around 300 kilometres from Samarinda, is the last town of any size on the navigable Mahakam and the jumping-off point for Kersik Luway, a small nature reserve with wild black orchids. Beyond Melak the river narrows, the forest closes in, and the journey starts to feel genuinely remote.