Papahānaumokuākea Marine National Monument

The Papahānaumokuākea Marine National Monument (pronounced [ˈpɐpəˈhaːnɐwˈmokuwaːˈkɛjə]; PMNM) is a World Heritage listed U.S. national monument encompassing 582,578 square miles (1.5 million km²) of ocean waters, including ten islands and atolls of the Northwestern Hawaiian Islands. It was first created by President George W. Bush in 2006 with an initial 140,000 square miles (360,000 km²). President Barack Obama expanded the Monument in 2016, increasing its area more than fourfold by moving its border to the limit of the exclusive economic zone, making it one of the world's largest protected areas.

The Monument is home to more than 7,000 marine species, one quarter of which are endemic to the Hawaiian Islands, with some only found in the Monument itself. Only 5.8 square miles (15 km²) of land remains above sea level, but it provides critical habitat for many terrestrial species. It also features ancient archaeological sites important to Native Hawaiians. The deeper waters are of interest to maritime historians, as it contains shipwrecks, submerged aircraft, and the remains of those who lost their lives in battles during World War II. As a protected area, the Monument is subject to a commercial fishing ban. President Joe Biden designated the marine areas of the Monument as the Papahānaumokuākea National Marine Sanctuary in 2025.