Above Spencer Beach is the Puukohola Heiau, a historic temple built by King Kamahameha I in the 1790s. It was constructed to fulfill a prophesy by wise men (Kahunas) to finally end the perpetual tribal wars in the islands. Heiaus take on many shapes and forms, from simple stone markers and fishing shrines to massive platforms for rituals with human sacrifice.
The larger heiaus were restricted for high priests and chiefs, so the public visits are prohibited except on special occasions. Today these places of worship are protected as a national treasure to preserve the Hawaiian heritage.
Petroglyphs (kii pohaku) are the rock carvings etched into lava stone centuries ago by native Hawaiians. Although the significance of petroglyphs are uncertain it's believed they're accounts of significant family and tribal events. The carvings tend to show human figures, canoes, turtles, fish, game, and other plain figures. They're found in many lava fields throughout the Island, especially where lava deposits are extensive and smooth.
The Puako Petroglyph Archaeological Preserve features a short trail marked with signs and interpretive information. The trail meanders through several smooth lava flows, and along the route are collections of petroglyph carvings called "images in stone." They're crude and roughly drawn, probably due to the primitive tools available - stone on stone.
Families were important and represented by the numerous figures of people, relatives, chiefs, dancers, and paddlers. Other glyphs show everyday life including turtles, dogs, birds, fish, tools, boats and mystical symbols. At the end of the trail was a large field with hundreds of carvings.