Introduction to Pearl Harbor: Pearl Harbor is named after the pearl oysters that were once harvested here. It is the largest natural port in Hawaii and the World War II Valor in the Pacific National Monument. Monument) and is the only U.S. Naval base named a National Historic Landmark. On December 7, 1941, the United States was suddenly attacked by the Japanese Navy and Air Force, killing 2,390 people and injuring hundreds. It also made the United States resolutely join the Second World War. The historical attractions of Pearl Harbor are still there. The USS Arizona Memorial, the USS Bowfin Submarine Museum and Park, and the Pacific Aviation Museum are all recorders of this historical event.