Puohokamoa Falls.

Around mile marker 11 look for a pullout along the road and a path leading down to the dramatic Lower Puohokamoa waterfall, which plummets 130 feet (40 meters). The upper waterfall, across the road, is more modest but still very worth a look. Also a  fun extra, you can  swim in the cool waterfall pools. Hana Picnic has more information and a free route map.