Smaller falls and rapids can be found several kilometres down a narrow, partially paved road that runs through a valley rimmed on either side by old-growth jungle. We believe that this road was once intended to continue all the way to Umphang, an isolated district in Thailand's far western frontier, but the plan was scrapped when environmentalists resisted in the 1990s. Rumour is that it's possible to undertake a seven-day trek along the planned route of this road, ending up in Umphang town. Bring a Thai speaker and chat up the rangers if you're interested.