Reasonably intelligent, suspenseful science-fiction drama which is still worth a look despite modern science/plate tectonics theory having rendered it largely superfluous. Fine acting by Dana Andrews and Kieron Moore help elevate the proceedings.
GORGO director Eugene Lourie supervised the special effects, and there are several standout sequences of miniatures photography, along with the usual requisite stock footage, some good and some NSG. There's also a well-handled set piece of thermal-suited scientists descending into a volcanic caldera in order to place an A-bomb that generates some good suspense. (We'll overlook the subsequent post-blast scene where there is disconcertingly no shock wave.) I saw this on a double bill (it was the 2nd feature) with a Japanese giant monster flick back in the 60's; can't remember the monster (maybe Ghidrah?) but this is the picture that sticks in my mind. The denouement is audacious and thought- provoking.