Thought to be the oldest luakini (temple dedicated to the war god Ku, often a place for human sacrifice) on the island, Holoholoku Heiau is located a quarter-mile up Kuamoʻo Rd on the left in the sacred Waimea River Valley. It's Kauaʻi's oldest known heiau and a place to pray for good fortune before battle.
A trail from there leads uphill to the gnarled headstones of an old Japanese cemetery with sweeping river views.