This narrow switchbacking trail drops 2000ft in elevation over 2.5 miles without offering much in the way of sweeping views, though there’s a river at the bottom. The climb back out of the canyon is for seriously fit and agile hikers only. Another option is to only hike about a mile down, where there’s a bench with an astonishing view.
To get to the trail, first find the Iliau Nature Loop trailhead just before Mile 9 on Hwy 550. Keep your eyes peeled for a small sign directing hikers to turn left and hike down the steep slope, with the hill at your back. When you hear the sound of water, you’re near the picnic shelter and Wiliwili Camp area, where overnight camping is allowed with an advance permit. Mostly it’s hunters who camp here.
Depending on weather, the sun can be unrelenting, so bring a hat and sunblock.