Hnaunau is part of the census-designated place of Honaunau-Napoopoo.Puuhonua o Hnaunau National Historical Park, also known as the City of Refuge, is located at Hnaunau. Hnaunau (also spelled Honaunau) is an unincorporated community on the island of Hawaii in Hawaii County, Hawaii, United States. It lies just off Hawaii Route 11 on the opposite side of the island from Hilo, the county seat of Hawaii County. Its elevation is 52 feet (16 m). Because the community has borne multiple names, the Board on Geographic Names officially designated it "Honaunau" in 1914 and 1954 before changing to the current spelling in 2000. Although it is unincorporated, it has a post office, with the ZIP code 96726.