Hike the Pipiwai Trail up to Waimoku Falls. A two mile trip each way, gaining 650 feet in elevation, it’s best to allow 3 to 4 hours to complete the trip. This beautiful waterfall drops 400 feet down a sheer lava rock wall. It is well worth the time, especially if you are a nature lover. You’ll see a wide variety of flora and fauna along the way, including a dense bamboo forest.