Waipio Valley Lookout is about an hour and a half from either Hilo International Airport or Kona International Airport on the North Eastern shore of the Island of Hawaii.
If you are using a GPS, the address is: Waipio Valley Lookout, 48-5546 Waipio Valley Road, Waimea, HI 96743
Parking in not permitted at Waipio Valley Lookout so you’ll have to find a place to park. Waipio Valley Artworks is a good option for parking for a small fee ($15 or so). It’s quite a trek to the trail head so if you can find a ride down the hill, it will save you a quite a hike before the hike.
If you can’t find a ride, hike down Waipio Valley Rd and around Lalakea Fishpond. The valley is approximately 1 mile wide and involves crossing through a sometimes waist high river which flows directly into the ocean. The crossing is deeper in the narrow sections and shallower in the wider sections. I prefer to cross in the wider/shallower part of the trail nearer to the ocean. On the other side you can see the western wall of the valley and the Muliwai Trail full of switch backs.
After crossing the Waipio Valley stream, you’ll hike through a wooded area to the trail head at the bottom of the cliff. The trial head is marked with a sign.