Must reserve entry tickets and can reserve up to 30 days in advanced
https://gohaena.com/
Kalalau Trail aka "Hanakapiai Trail." This trail includes the first two miles (one way) of the 11-mile Kalalau trail that stretches along the NaPali coastline, starting at Kee Beach at the end of the road on North Kauai.
It is popular with visitors who want a very scenic half-day hike. It can be semi-strenuous, however, as the trail does do a good bit of climbing and descending. Crossing the stream at Hanakapiai Beach can also be hazardous, but overall this is a good trail for visitors who want to see some of NaPali's beautiful coastline on foot.
Halemanu Rd, Waimea, HI 96796
As mentioned, the Waipoo falls trail leads to the top of the falls where you’ll be able to witness only the initial 25 foot portion of the waterfall. Nevertheless, do the hike as it has a lot of surprises in store for you.
View from the Lookouts
The first lookout (Waimea canyon overlook) is along Highway 550, a little past mile marker 10. The next one (Puu Ka Pele lookout) is past mile marker 13 and has a closer view of the falls and canyon. This is the best viewpoint of the two. Both lookout points are great photo opportunities not to be missed at any cost.