Whats the name of this movie?

Hey, the movie is about 2 men, i believe 1 is a professor and the other his student and they made some kind of machine to go to the earths core. Once they reached the Earths core they realize its a whole world under there with people and other creatures. They end up being captured by these monster looking people who feed the Core People (look like cave men) to these dragon like birds who can hypnotize the people and make them do as they wish. At the end, the 2 men escape, save the people and the younger guy ends up fighting one of the cave men dudes for the right to be with a woman he met down in the Core. ..hope someone can help. Thanks :)