"무적함대" (Invincible Fleet) refers to the naval forces of the Joseon Dynasty in Korea during the late 16th century. This fleet is best known for its role in the Imjin War, where it defended Korea against Japanese invasions. The fleet was led by the famous admiral Yi Sun-sin, who is celebrated for his innovative tactics and the use of the turtle ship, an armored warship. The term "무적함대" highlights the fleet's reputation for being formidable and effective in battle. Despite facing overwhelming odds, the fleet achieved significant victories, contributing to the eventual repulsion of Japanese forces. The legacy of the Invincible Fleet remains a symbol of national pride in Korea.