The Girl from Rio (1969)

Secret agent Jeff Sutton arrives in Rio with $10 million dollars, and finds himself embroiled in a war between Sir Masius, a British mobster, and the megalomaniacal Sumuru. From her secret city, "Femina", Sumuru assembles an army of women with which she will conquer the world. Masius, hoping to find Femina and steal Sumuru's riches, tries to use Sutton as his pawn. Ultimately, Sutton leads a squadron of helicopters on an attack on Femina. Knowing she's beaten, she chooses to destroy Femina rather than let Masius have its wealth. Sutton barely makes it out of Femina before it self-destructs, presumably killing both Sumuru and Masius. Nevertheless, the film concludes with Sumuru aboard a ship leaving Rio, joined by a group of women who are apparently her followers.