Waterfall Jao Leuam

In the north of the island, before the ferry pier, there's a 7-11 with a sign directing you to Waterfall Jao Leuam, 4 km away which took less than 10 minutes on a motorbike. The road's narrower but paved until the last little bit, when it's becomes a bumpy dirt road.

It costs 40 baht to enter since it's apparently "private property". Despite all the the points of interest signposted, we couldn't paths beyond the waterfall so it took about 30 minutes in total to hike to the last level of the waterfall and back.
It took maybe 5 minutes of easy hiking to get to the first level of the "waterfall". Signs indicate 5 levels, but really don't expect too much as they're all quite small and equally unimpressive. The path gets a bit rockier but still not difficult although it probably helps to be wearing sensible shoes. It took less than 15 minutes to get to "level 5" of the waterfall - then we couldn't find any more paths.

If you have limited time on the island, maybe go to other waterfalls, like Klong Plu Waterfall.