The captivating triple-tiered Uma Uma Falls is only accessible through the Umauma Experience; it is no longer accessible through the World Botanical Garden.
Despite what you may read on some signs from the WBG, you will pay the Umauma Experience $10-12 (as of this writing) for the exclusive privilege of visiting the falls.
The hike is accessible by entering mauka (toward the mountain) where the Umauma Experience sign is located over the road, up the driveway, and you'll park to the left of where you will pay your entry fee. The Umauma experience offers a variety of activities, including a self-guided tour of the garden, ATV rides, and Ziplining. The three levels which Uma Uma Falls flows down resemble great lava stone steps with recesses that create tranquil little pools surrounded by tropical plants and trees.
Make sure to dab a little bug spray on, mosquitoes can frequent this area.
Go 16 miles north of Hilo on the Hawaii Belt Road (Hwy 19). At Mile Marker 16, take the road inland. Turn right and look for signs to the Umauma Experience (Google maps also has the correct location).