The river narrows perceptibly as it continues to Kota Bangun, a small town three hours from Samarinda by bus. A single short stretch of tarmac marks the centre of the town’s commercial area. Market stalls and warung line the street either side of the main pier. There are plenty of opportunities to charter private boats from the town to explore villages upstream. It’s essential to arrive by 3pm so you’ll reach the river villages before dark.