Perched around the highest sea cliffs on the island (at 1080ft above sea level) is a vast archaeological site home to the largest collection of ruins on Lana'i. It's easy to get goosebumps wandering the structures of this ancient Hawaiian village, complete with houses, shrines, petroglyphs and ceremonial sites. In the 1790s King Kamehameha used it as a vacation spot between battles. He enjoyed fishing for kawakawa (bonito) here and famously took leaps into the ocean from a 60ft platform.
A highlight is the Halulu Heiau (Temple of Halulu), where those who broke kapu (ancient Hawaiian law) could opt for self-imprisonment and potentially be absolved of their wrongdoing. The structure of the temple still remains intact up to a few meters high.
The well-marked Keālia Kapu-Kaunolū Heritage Trail, with information boards throughout, runs 0.5 miles around the sites and structures, such as a fishermen's shrine and a canoe longhouse. You'll likely have the place to yourself.
To reach little-visited Kaunolu from Lanaʻi City, follow the Kaumalapaʻu Hwy (Hwy 440) 0.6 miles past the airport, and turn left onto a partial gravel-and-dirt road that runs south through abandoned pineapple fields for 2.2 miles. A carved stone marks the turn onto a much rougher but still 4WD-accessible road down to the sea. After a further 2.5 miles you'll see a sign for the heritage trail. Another 0.3 miles brings you to a parking area amid the ruins. Private tours are possible with Rabaca.