Introduction to military relics: Hebao Island was a military fortress in the South China Sea during the war years. It still retains a large number of military facilities, such as observation towers, bunkers, air-raid shelters, etc., recording the historical facts of Japan's invasion of China and the heroic deeds of the navy stationed on the island. , and the "big windmill" donated by the United Nations Red Cross. These historical relics add a mysterious color to Hebao Island tourism.