Atlantis, the Lost Continent

Atlantis, the Lost Continent is a 1961 American science fiction film in Metrocolor, produced and directed by George Pal for MetroGoldwynMayer, starring Sal Ponti aka Anthony Hall, Joyce Taylor, and John Dall.

A Greek fisherman named Demetrios Sal Ponti, under the screen name of Anthony Hall and his father rescue Princess Antillia Joyce Taylor from a shipwreck without knowing that she is from the technologically advanced civilization of Atlantis. After rescuing the princess, Demetrios must travel beyond the Pillars of Hercules to take her home. After they are picked up at sea near Atlantis by a giant fishlike submarine boat, Demetrios, expecting to receive a reward for returning Antillia, is instead enslaved and forced to work in the crater of the volcano which dominates the center of the continent.King Cronus Edgar Stehli is being manipulated by an ambitious usurper, Zaren John Dall, collaborating with an evil sorcerer, Sonoy the Astrologer Frank DeKova, who wishes to use the resources of Atlantis in order to conquer the known world. From the continents volcano, the slaves of Atlantis have been mining unique power crystals which absorb the suns rays and can then be used to fire heat ray beams. The crystals were originally used to produce light and heat for individual Atlanteans, but due to its arrogance, corruption, and moral laxity, Atlantis has now become an abomination before Heaven. ........

Source: Wikipedia