One of the most important ancient sites on the island, Kukaniloko Birthstone State Monument is located in a 5-acre field just north of Wahiawa township, on the western side of the Kamehameha Hwy. Wahiawa is considered the piko (navel) of Oʻahu. The 180 lava-rock stones that make up the monument, once used as a royal birth site, are believed to possess the power to ease the pains of giving birth and are thought to be more than 900 years old.