Kealakekua Bay, south of Kona on the Big Island, serves up a buffet of tourist attractions: The Cook Monument snorkeling haven, Kealakekua State Park heiau (temple), and the sprawling grounds of Pu'uhonua o Honaunau National Historic Park, beside which is Two Step, one of the best snorkeling spots in the world.
It's no wonder that many visitors miss Pu'uhonua Beach Park at the south end of the historic park. Here palm-shaded picnic tables are placed along a lava reef that has several excellent kid's swimming ponds, and the Ki'ilae Village Coastal Trail begins a historic route that can walk the legs off the most energetic of hikers. Much of the good stuff is within a mile of the trail head.
You immediately pass the rock foundations and other ruins that remain from one on Hawaii's last-inhabited ancient villages and then hop up to the Keane'e Cliffs on a boulder ramp that was a main feature on this "highway" in the mid-1800s. (People jump from the cliffs, a practice frowned upon by the Park Service.)
The official trail (park boundary) ends after a mile or so, but the historic route continues for several miles to Ho'okena, a much-more-direct route than taking the modern paved highways. For trail directions consult your Hawaii Big Island Trailblazer and if you don't have one they're available for purchase on Amazon.com and BarnesandNoble.com.