Name of an old movie that ends with the main characters traveling "North, always North"

I'm pretty sure it's The Land That Time Forgot (1975). The movie has a WWI German U-Boat with the survivors of a sunken British ship which

happen across an uncharted sub-continent called Caprona, a fantastical
land of lush vegetation where dinosaurs still roam, co-existing with
primitive man.

I remember the scene with the U-Boat firing on the Styracosaurs (not Triceratops actually). Also from Wikipedia, the movie ends with

Bowen Tyler and Miss Lisa are stranded, and forced to move northwards.