Atragon

Original title: 海底軍艦

“The dreaded undersea kingdom challenges the surface! The emergency dispatch of the all-purpose atomic battleship!”

Directed by Ishirō Honda

The legendary empire of the lost continent of Mu reappears to threaten the world with domination. While countries unite to resist, an isolated World War II Captain has created the greatest warship ever seen, and possibly the surface world's only defense.