The Nā Pali Coast State Park encompasses 6,175 acres (2,499 ha) of land and is located in the center of the rugged 16 miles (26 km) along the northwest side of Kauaʻi, the oldest inhabited Hawaiian island. The Nā Pali coast itself extends southwest starting at Keʻe Beach extending all the way to Polihale State Park. The na pali (high cliffs) along the shoreline rise as much as 4,000 feet (1,200 m) above the Pacific Ocean. The state park was formed to protect the Kalalau Valley.
Although inaccessible to vehicles, this coast can be enjoyed over land by hiking or in a helicopter, and from the ocean by kayak and paddleboard. Charter tours are available on rigid-hulled inflatable boat or catamaran, originating from Port Allen and Hanalei Bay. The Kalalau Trail from the end of Hawaii Route 56 (called the Kuhio Highway) provides the only land access along the coast, traversing 11 miles (18 km) and crossing five major valleys (and many smaller ones) before reaching Kalalau Beach at the base of Kalalau Valley. Side trails along the way lead to waterfalls in the valleys above.
To the east of the state park is the Hono O Nā Pali state Natural Reserve. It was established in 1983, and then extended to over 3,578 acres (14.5 km2) in 2009. Hiking trails and hunters roads have access to the sharp ridges from Koke Road (route 550) in Waimea Canyon.