When I was young(er) I spent a lot of time playing Dungeons & Dragons. One of the things I enjoyed most was drawing maps of monster-filled catacombs and dangerous wildernesses: places that only existed on graph paper and in my imagination.

Lately I’ve gone back to looking at maps of imagined places. Only these maps weren’t drawn by a Dungeons & Dragons nerd in suburban Melbourne in the mid-1980s — they were drawn by European cartographers hundreds and hundreds of years ago. And the imagined place on these maps isn’t a dragon’s lair filled with treasure and experience points; it’s Australia.

Well, sort of.

I’ve been looking at maps for my new book, Explorers: filling in the map of Australia. I’ve looked at everything from the four hundred year old chart of the Duyfken, the yacht that made the first known European landing on Australia, through to maps drawn after Federation in 1901, once most of the continent had been explored.

Some of the most fascinating maps are the ones drawn before Europeans had fully charted the oceans of the southern hemisphere. The 1570 world map below, drawn by Flemish cartographer Abraham Ortelius, shows a gigantic continent twice the size of Antarctica in the southern oceans. This enormous landmass is named Terra Australis Nondum Cognita (‘the great unknown south land’, also called Terra Australis). The familiar outline of Australia as we know it today is nowhere to be seen.

Map of the world, 1570. Ortelius, Abraham. Typus orbis terrarium. MAP NK 10001. National Library of Australia. Reproduced with permission

Ancient Greeks had speculated about the existence of a ‘great southern continent’ at least as early as the fifth century BC. They reasoned that a large landmass must have existed in the unexplored southern hemisphere to balance the land that was known to exist in the northern hemisphere. Ortelius’s map imagines what this land might have looked like, based partly on information gained from the voyages of Ferdinand Magellan and Marco Polo, but mostly by making lots of guesses.

Even toward the end of the eighteenth century, three hundred years after Ortelius drew his map, Europeans were still searching for something resembling Terra Australis. But by the time James Cook had made his second voyage (between 1772 and 1775), the mirage of the southern continent had melted away into the smaller continents of Antarctica and Australia, the islands of New Zealand, and the other islands of the South Pacific.

So, just as the people in the mid-twentieth century dreamed of going to the moon (check), and just as we now dream of setting foot on Mars (working on it) and travelling beyond the solar system (one day), the Ancient Greeks were dreaming of a gigantic continent on the other side of the world. Their ships weren’t advanced enough to reach it, so they could only imagine the strange creatures and fantastic treasures waiting to be discovered there…

It’s starting to sound a bit like Dungeons & Dragons after all.