The Kalalau Trail is a difficult hike. It's 11 miles long; grueling in it's elevation loss and gain; narrow and often muddy; slippery when wet and loose when dry; but the views all along the trail are always pretty good. This one is one of my favorites. Probably around 1.75 miles into the trail you get the opportunity to look down onto Hanakapi'ai Beach through typically lush Na Pali vegetation.
Kalalau Trail, Kauai