The Kalalau Trail snakes along the Napali Coast, climbing over coastal bluffs to reach verdant river valleys and beaches free of human development. The route is challenging, and most hikers are content to make the two-mile trek to the Hanakapiai Beach, or add on two more miles to climb the river valley and reach a scenic waterfall. Photo: Michael Utech/iStock

With cliffs rising abruptly from the sea to heights of nearly 4,000 feet, it’s easy to see why the Napali Coast has thwarted road builders, and remains free of modern development. Yet despite the remote nature of the coastline, the valleys that lie hidden between these forbidding headlands were once settled by native peoples. Photo: Agnieszka Gaul/iStock

When seas are calm, the beaches and valleys of the Napali Coast can be reached by boat. A favorite destination is the ancient Hawaiian fishing village Nualolo Kai, which sits on a thin strip of coastal lands overlooked by sheer cliffs. Once a significant settlement, it is now an archeological preserve. Photo: iStock

A strenuous eight-mile hike on the Kalalau Trail leads to a unique rock formation. When the top of this large sea cave eroded and collapsed, it left a 50-foot archway that opens into a circular bowl of churning surf. When weather permits, this site can also be visited by tour boat. Photo: iStock

A view from the Kalalau overlook takes in the wild valley of the same name, which lies in the center of the Napali Coast, and has been featured in a number of films from King Kong to Jurassic Park. No roads lead downward, but a network of trails provides access for hikers and campers who come to experience a truly wild tropical setting. Photo: iStock