If that wasn't enough, now they are claiming that Australia does not exist.
Yes, the country of Australia, home to more than 24 million people, a member of the British Commonwealth, which was a home for indigenous Australians thousands of years before the British arrived, the country that gave us Kylie, Nicole Kidman, Mad Max, Home and Away and Wolverine, is not real.
According to The Mirror, this theory was spouted at the convention and has since been doing the rounds on social media.
The theory began in 2017 by a Swedish Facebook personality named Shelley Floryd.
indy100 covered the story at the time, but thanks to its reemergence at the Flat Earth Convention it is beginning to pique conspiracy theorists' interests again.
The now-deleted Facebook post claims that Australia was created as a cover-up for a mass murder by the British after they shipped criminals into the middle of the ocean in the 18 century and drowned them.
That's a horribly grim image, but what about the actual Australians who live there and the actual photos and footage made there? How about people who have visited there on their travels?
We'll allow Shelly to try and explain:
Australia does not exist. All things you call 'proof' are actually well-fabricated lies and documents made by the leading governments of the world.
Your Australian friends? They're all actors and computer-generated personas, part of the plot to trick the world.
If you think you've ever been to Australia, you're terribly wrong.
The place pilots are all in on this and have in all actuality only flown you to islands close nearby - or in some cases, parts of South America, where they have cleared space and hired actors to act our as real Australians.
We're actually not quite sure where to begin with that, but we fail to see what it has to do with the Earth being flat and just strikes us as a bit of nonsensical ramble.
If you thought that was weird, wait till you hear what's going on next door to Oz, in New Zealand, which is being routinely left out of world maps.
Don't believe us? Here is a map that we have found today which has completely erased New Zealand.
Why is this? Are Australians trying to steal their tourists or are they trying to discredit the Kiwi wine industry?
It's probably nothing more than an oversight, but this epidemic has not gone unnoticed and has been covered by the likes of the BBC and The Telegraph in the past six months.
There is even an entire Reddit thread dedicated to finding maps that don't include New Zealand.
Anyway, the Kiwi's themselves are attempting to solve this problem and have launched a campaign starring New Zealand's Prime Minister and comedian Rhys Darby to help save New Zealand from being forgotten from maps forever.