Robert Brown (Akhoba) wears makeup identical to that worn by Lon Chaney Jr. wore in the same role in the 1940 version (One Million B.C.).
As the Shell People are attacked by a giant turtle, the women call it "Achelon" which is the real scientific name for the animal.
The exterior scenes were filmed in the Canary Islands in the middle of winter, late 1965. Principal photography finished in January 1966, with Ray Harryhausen completing his effects by spring.
This was promoted as Hammer's 100th production.