This movie's a variation on the "men-are-stranded-with-lost-civilization-of-sex-starved-women" theme. A WWII bomber is forced down in the ocean, and after paddling their raft for a few days, the surviving men come ashore on the usual uncharted island, which is ruled by a race of women descended from the Druids (!).
That's only the beginning of the fun, as the women are constantly pestered by "The Hairy Men", who are a bunch of actors dressed in animal skins and covered by fake hair. A few of the usual shots of lizards from "One Million Years B.C." are thrown in, there are battles with the "Hairy Men", and a volcanic eruption climax predictably ends the movie. The whole implausible story is told by Conrad in flashback to serious doctor Lyle Talbot and a nurse, who find the whole story a bit wild until "evidence" of its veracity is uncovered in the final shot.
This movie is entertaining due to its bizarre plot, laughable dialogue, and plentiful action sequences. There's nothing quite like it, to be sure, so watch with an open mind.
P.S.: Nomination for the movie's best line: "Ed, stand guard. Shoot anything with hair on it that moves!"