Papahānaumokuākea Marine National Monument is the single largest conservation area under the U.S. flag, and one of the largest marine conservation areas in the world. Extensive coral reefs can be found below the water surface, housing over 7,000 marine species. Many of the islands and shallow water environments are vital habitats for species such as the threatened green turtle and the endangered Hawaiian monk seal. Land areas also provide a home for unique bird species, including the world's most endangered duck, the Laysan duck. In addition to the importance to marine wildlife, this sanctuary has significant cultural importance to Native Hawaiians. Visitors can enjoy this cultural and marine conservation site with activities such as snorkeling, diving, and interactive educational exhibits in the visitor center. To learn more about this sanctuary, visitors should stop by the Mokupāpapa Discovery Center.