- The Pipiwai Trail is a moderately difficult, four-mile (round trip) hike through a rain forest to Waimoku Falls. The trail passes Makahiku Falls approximately one half mile from the trailhead. It ends upstream, near the base of Waimoku Falls. The clear pools formed by the smaller waterfalls along the trail make excellent places to swim, although flash flooding may occur. Insect repellent is a must for this hike.