Archeology of the “Mystery Islands” Nihoa and Mokumanamana

Heiau on Mokumanamana.

U.S. Fish and Wildlife Service

Nihoa and Mokumanamana (Necker) Islands are part of the northwestern Hawaiian island chain. Both contain archeological remains such as terraces; platforms; and large, upright stones. While the islands were referenced in Hawaiian mo’olelo (stories and oral traditions), the first European sailors and explorers saw physically-abandoned sites with unknown meaning. This led to the nickname the “Mystery Islands” (Kikiloi, 121). Today, archeological studies and oral histories
have shone a light on the islands’ significance to people of the past.

In 1857, King Kamehameha IV annexed Nihoa and Mokumanumanu into the Hawaiian kingdom. Twenty-eight years later, his daughter Princess (later Queen) Liliuokalani and 200 others took an exploratory visit to Nihoa. The Queen brought back a carved basalt bowl that she collected on the island. This bowl was one of many reminders of the people living on Nihoa centuries before, yet little else of the islands’ histories was known at that time.
It took until 1923 for scholars of the Tanager Expedition to conduct the first archeological surveys of Nihoa and Mokumanumanu. The following year, Kenneth Emory from the Bishop Museum directed a second archeological study. His team recorded open habitation sites and cave shelters, agricultural terraces, and heiau (temples) on both islands. At the former sites, Emory’s crew uncovered hearths, stone tools (such as hammerstones, awls, sinkers, and fishhooks), and other domestic items including jars and bowls similar to the one collected by Queen Liliuokalani years earlier. Emory noted that heiau vastly outnumbered habitation sites on Mokumanamana. Many heiau were built in a specific form with a semi-circle of upright, carved stone images (ki’i) and a paved stone floor enclosed with a wooden or rock fence or wall (Kikiloi, 76.) Several contained coral offerings.
Ki'i head and torso
Stone image (ki’i) from Mokumanamana Island.

Metropolitan Museum of Art

In 2012, Dr. Kekuewa Kikiloi of the University of Hawaii expanded upon Emory’s findings. Kikiloi used mo’olelo, historical documents, and archeological excavations to uncover the complex ritual system that took place on the islands between 1400 and 1800 CE (Common Era). His work highlighted two concepts within Hawaiian religion. The first is mana (spiritual power and authority) which can be passed down between ancestors and their living descendants. The second is the importance of seasonal changes within the ritual calendar. The summer solstice marked the transition between Makahiki (four months of peace and harvest) and Kau wela (eight months of production). Around this time, competing chiefs within the past would demonstrate their strength by amassing resources to build heiau for ‘aha (braided cord) ceremonies (Kikiloi, 96). These ceremonies would ensure the passing on of mana, and the ancestors’ help and protection in the coming time of production.

Mokumanamana was an optimal place for these heiau. According to mo’olelo traditions, Wakea, the Sky Father, built a heiau with his hands for his ancestors when asking for their aid. The ritual sites on Mokumanamana were all found on its five hills, which naturally mimic Wakea’s cupped hand; indeed, the island’s name translates to the “island [temple] of fingers” (Kikiloi, 92). In addition, because of the island’s position within the Pacific Ocean, the sun is directly overhead on the summer and winter solstice. This phenomenon made the island a direct marker of the Hawaiian spiritual calendar. Therefore, by building heiau on Makumanamana, chiefs directly connected themselves with multiple forms of ritual power.

Unlike Mokumanamana, Nihoa contained several long-term habitation sites and agricultural terraces as well as heiau. It is likely that individuals in the past lived there year-round and helped produce the wood and other resources that supported the short-term yet essential ritual sites on Mokumanamana.

Today, Nihoa and Mokumanamana are listed on the State and National Registers of Historic Places. The islands are part of the Hawaiian Islands National Wildlife Refuge within the Papahanaumokuakea Marine National Monument. In 2010, Papahanaumokuakea was named a World Heritage Site. To protect these incredible resources, access to the islands is permitted for scientific, educational, or cultural purposes only.


Cultural Features: Monument Features and Papahanaumokuakea’s Archaeological Resources. Papahanaumokuakea Marine National Monument. National Ocean Service, Office of National Marine Sanctuaries, National Oceanic and Atmospheric Administration.

Bishop Museum. Islands of Mystery: The Archaeology of Nihoa and Mokumanamana. Ka’elele (Summer 2016):17.

Brigham, William Tufts. Ancient Hawaiian Stone Implements. Issued April 1902. Memoirs of the Bernice Pauahi Bishop Museum of Polynesian Ethnology and Natural History, Volume I. Bishop Museum Press, 1899-1903.

Emory, Kenneth P. Archaeology of Nihoa and Necker Islands. Tanager Expedition No. 5, Bernice P. Bishop Museum Bulletin 53. Honolulu, 1928.

Kikiloi, Kekuewa Scott T. Kukulu Manamana: Ritual Power and Religious Expansion in Hawai’i: The Ethnohistorical and Archaeological Study of Mokumanamana and Nihoa Islands. Dissertation, University of Hawaii, 2012.

Mokumanamana (Necker Island). Hawaiian Islands National Wildlife Refuge. U.S. Fish and Wildlife Service.

Last updated: March 6, 2023