If that seems too unbelievable, compare with those maps, this map done by the famed Tyrolean cartographer and artist Heinrich C. Berann for the National Geographic Society beginning in 1966. It clearly shows the continent of Antarctica without its cover of ice. The intriguing detail here is that there are underwater passageways that run nearly the entire length of the continent and seem to converge at the exact location identified as the opening into the hollow earth!
“Truth is stranger than fiction, but it is because fiction is obliged to stick to possibilities; truth isn’t.”
– Mark Twain