Puʻu o Mahuka is a major Hawaiian temple complex on Oʻahu’s North Shore, the island’s largest heiau and one of its most important surviving ceremonial sites. Built in stages between the 17th and 18th centuries, it included a luakini heiau associated with rites for success in war and was deeply tied to the political and religious life of late pre-contact Oʻahu. Its hilltop setting above Waimea Bay gave it ceremonial, observational, and defensive importance, including links to Makahiki and coastal watching. The site remained in use after Kamehameha I’s conquest of Oʻahu until the kapu system ended in 1819, and it later received national historic recognition.