The Selangor River — Sungai Selangor — runs down from the Titiwangsa range and through the valley below Kuala Kubu Baru before widening into the Selangor Dam reservoir downstream. The stretch above the dam runs through a forested gorge and is the main white-water rafting river in peninsular Malaysia. Guided half-day trips take groups through a series of grade two and three rapids — enough to keep things exciting without requiring prior experience.
Several operators run trips departing from KKB town, typically in the mornings. Most trips last around two to three hours on the water, followed by a riverside lunch. The river is fed by highland rainfall, so water levels and rapid intensity can vary; operators will usually advise on conditions. The surrounding forest is largely intact, and the gorge is scenic even in the calmer stretches between rapids.