The Cavern is a 1964 Italian-German-American war-drama film directed by Edgar G. Ulmer. This was his last film as a director. It was one of a number of war movies John Saxon made outside Hollywood.

Edgar Georg Ulmer was a Jewish-Moravian, Austrian-American film director who mainly worked on Hollywood B movies and other low-budget productions, eventually earning the epithet 'The King of PRC', due to his extremely prolific output for the Poverty Row studio. His stylish and eccentric works came to be appreciated by auteur theory-espousing film critics in the years following his retirement. Ulmer's most famous productions include the horror film The Black Cat (1934) and the film noir Detour (1945).