Papahānaumokuākea is the United States' only mixed (cultural and natural) World Heritage site. The name Papahānaumokuākea commemorates the union of two Hawaiian ancestors - Papahānaumoku and Wākea - who gave rise to the Hawaiian Archipelago, the taro plant, and the Hawaiian people. Comprised of a vast cluster of small, low lying islands and atolls, with their surrounding ocean, the area has deep cosmological and traditional significance for living Native Hawaiian culture, as an ancestral environment, as an embodiment of the Hawaiian concept of kinship between people and the natural world, and as the place where it is believed that life originates and to where the spirits return after death. On two of the islands, Nihoa and Makumanamana, there are archaeological remains relating to pre-European settlement and use. Much of the monument is made up of water habitats, with notable features such as seamounts and submerged banks, extensive coral reefs and lagoons. It is one of the largest marine conservation areas in the world.