Turn to the left after 16 mile maker of the Route 19 to north, you can see the gate of the "World Botanical Garden" and turn to the left here, you'll go to the Falls of three steps in the virgin tropical rain forest, named "UmaUma Falls". World Botanical Garden is on the way of constructing, but you can see them paying $8. Also you have to pay entrance fee if you visit gate and get map, even just want to see the falls only.
Although it is not famous but I have never seen such elegant falls. It is better to bring coffee or something to wallow in this quiet and peaceful atomosphere.