The esplanade runs for several kilometres along the Kemena River, which empties into the South China Sea just beyond the town's edge. It's a utilitarian piece of urban infrastructure — wide concrete walkway, some benches, a few food stalls in the evening — but it's where Bintulu's residents actually go to walk, and it gives a clear sense of the town's relationship with its river. Fishing boats move upstream and downstream throughout the day; the opposite bank is still largely mangrove.
The best time to come is around sunset, when the light on the water is decent and the evening food vendors set up. Don't expect a scenic waterfront by Southeast Asian tourist-town standards — Bintulu hasn't been landscaped for visitors — but it's a perfectly functional place to spend an hour, and it connects directly to the Tua Pek Kong Temple and Pasar Tamu at the Main Bazaar end.