North of Waimea in Kokee State Park on Kauai, the 11 mile Nu alolo / Awa- awaphui Loop is a strenuous hike requiring most of a day. The route offers amazing views and solitude. The loop follows a ridge and runs through a rain forest.
There are three main sections of trail. The Nualolo Trail starts just south of the Kokee Lodge on Kokee Road (SR550) on the right hand side coming from the Lodge. This 3.75 mile trail runs northwest through montane forests and lowland dry shrubland towards the ocean while descending 1,600 feet. The trail opens to an amazing view of the ocean and Na Pali Cliffs. The Nualolo Cliffs leads northeast to the Awa-awapuhi Trail. Then, follow Awa-awapuhi Trail 3.25 miles southeast ascending 1,600 feet back to Kokee Road (SR550). There is about 2,000 feet of vertical climbing along the route.
Here are some notes on adventuring in Hawaii. First, unlike mainland forests, the tropical island forests can grow very dense and can mask dropoffs. Plus, the trails can be very wet and slick most of the year (December to February is the main rainy season, but expect rain all year round). Stay on the trail to avoid disorientation. Second, speaking of disorientation, be aware that most Hawaiian topographic maps use the Old Hawaiian Datum. When trying to use the latitude/longitude from those maps with a GPS unit, you will think you are 0.4 miles south/southeast of where you really are. Kind of important in a dense jungle. Third, the bacteria Leptospirosis is found in the local waters and mud. It causes flu like symptoms within 2-20 days of contact, and can be fatal if not treated with antibiotics. Fourth, when hiking about, walking sticks can be very helpful for stablity in the slick conditions, for probing mud hole depths and clearing webs of the tiny crab spider.
Overall, Nu alolo Trail / Awaawapuhi Loop is the 6th most popular walking & backpacking of all 45 hiking in Hawaii.