According to what I've learned recently. Flat earth proponents believe that the South Pole does not exist.
http://www.atlanteanconspiracy.com/2015/06/south-pole-does-not-exist.html
Rather "south" is a 360 degree circle surrounding the flat plane of the earth while the North Pole, which apparently does exist, is the center point of earth.
Now one big problem with this is the stars. For instance, Crux. One of the most easily recognized constellations.
It is visible only in the southern hemisphere. (globularly thinking).
The problem with the Flat Earth theory is that the Southern Cross really exists. I've seen it and probably millions of other people see it every night. For centuries it has been used for navigation. If "South" is all around us. How can the Southern Cross always appear where it belongs, in the southern sky wherever on earth one happens to be? Are there an infinite number of Southern Crosses? Is the constellation a hologram that is triggered instantaneously and separately by every individual conscientiousness that happens to be close enough to the edge of the world and looks south, or should I say "outward?" on a clear night?
There is simply no way that I can conceive of to explain how the stars can be and definitely are always where they are supposed to be in a flat earth reality.
It would be easier to believe in a Matrix reality.
Sorry, But The Flat Earth Theory Has Just Been Debunked.