The gentle, 1.3-mile round-trip to Puʻu Loa (roughly, 'hill of long life') leads to one of Hawaiʻi's largest concentrations of ancient petroglyphs, some over 800 years old. Here Hawaiians chiseled more than 23,000 drawings into pahoehoe (smooth-flowing lava) with adz tools quarried from Keanakakoʻi. Stay on the boardwalk – not all petroglyphs are obvious, and you might damage some if you walk over the rocks. The trailhead parking is signed between Miles 16 and 17 on Chain of Craters Road.

There are abstract designs, animal and human figures, as well as thousands of dimpled depressions (or cupules) that were receptacles for piko (umbilical cords). Placing a baby's piko inside a cupule and covering it with stones bestowed health and longevity on the child. Archaeologists believe a dot with a circle around it was for a first born, while two circles were reserved for the first born of an ali`i (chief).