Be careful when parking to go look for hidden waterfalls. The road is narrow and the tour buses get pretty close. Look for vehicles parked along the road if there is no obvious scenic view.
The Road to Hana is a long trip to make, but worth it to have access to the western side of the island. Waterfalls are sometimes hidden behind the trees so having an experienced guide really helps. Not all waterfalls can bee seen from the road. They have a little color change depending on the amount of rain they have. The color change in this photo contrasts nicely from the expected green.