hui R.
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The waterfall is spectacular but you get quite a limited view on it from a few viewing platforms, as it's not possible to hike down as a regular tourist. There seem to be quite limited things to do in the national park as well.
During off season, food and coffee options nearby are also closed due to a shortage of visitors, you'd have to drive pretty far to find something to eat, maybe even to the nearest big town, Khun Yuam. It's worth a visit if you're in the area though.