I saw a new movie this weekend called
JOURNEY TO THE CENTER OF THE EARTH, starring Brendan Fraser.
It was an interesting twist on the H. G. Wells book by the same name written in 1864...

they found an entrance to another world inside the Earth, similar to the one Hollow Earthers claim that was discovered by Admiral Byrd---first in the North Pole and later in the South Pole, although of course this has never been conclusively proven or widely accepted. In the science fiction book, on a beach covered with bones, Axel discovers an oversized human skull. Axel and Lidenbrock venture some way into the prehistoric forest, where Professor Lidenbrock points out, in a shaky voice, a prehistoric human, more than twelve feet in height, leaning against a tree watching a herd of mastodons. This part was not in the new movie, however they did encounter dinosaurs in the new movie.

You can read more about Admiral Byrd and the so-called "Hollow Earth Theory" here, be advised, I am in no way endorsing the writings of Rodney M. Cluff or his website, but with regard to the material about Admiral Byrd as written by Dr. R. W. Bernard, to me some parts are kind of interesting as shown here:
http://www.ourhollowearth.com/Bernard/Chapter1.htm

I did find it interesting that there was a well-documented and massive military expedition into the Antarctic, organized by Admiral Byrd back in the 1940's called OPERATION HIGH JUMP, Wikipedia describes it as follows:

"Operation Highjump was the largest Antarctic expedition to date. Conspiracy theorists specializing in alleged Aryan or Nazi activities in Antarctica have extensively speculated about this mission. In 1946, US Navy Secretary James Forrestal assembled a huge amphibious naval force for an Antarctic Expedition expected to last six to eight months. Besides the flagship Mount Olympus and the aircraft carrier Philippine Sea, there were thirteen US Navy support ships, six helicopters, six flying boats, two seaplane tenders and fifteen other aircraft. The total number of personnel involved was over 4,000. The armada arrived in the Ross Sea on 31 December 1946, and made aerial explorations of an area half the size of the United States, recording ten new mountain ranges. The major area covered was the eastern coastline of Antarctica from 150 degrees east to the Greenwich meridian. The expedition was terminated abruptly at the end of February 1947, six months early, the entire remaining armada returning immediately to the United States. The early termination of the mission was never explained."
http://en.wikipedia.org/wiki/Richard_Evelyn_Byrd