Atragon (1963) - American Theatrical Trailer

The Mu empire, an underwater civilization that sank to its present location a millennia ago, proclaims a battle cry to the Earth. The submerged kingdom declares war against all nations, destroying US subs and Japanese ships while causing disasters like earthquakes to befall cities. Humanity's hope falls on a single ship, one originally envisioned to win World War II. That ship, the Gotengo, was an all purpose war machine: capable of air, water and underground combat. Created by Captain Hachiro Jinguji, the man was a patriot, filled with an unbending honor toward his country. Jinguji had revolted against the surrender of Japan in World War II, and ever sense had planned to use the Gotengo as the tide turner when Japan was to remobilize. Jinguji did not see the Mu as the threat he was waiting for. He ultimately realizes their danger after they kidnap his daughter, which sends the Gotengo into action...