Since classical antiquity, there have been tales of legendary islands in the Atlantic — phantom islands that appear and disappear at will, floating islands that travel untethered across the sea. Some islands, it might turn out, aren’t islands at all, but great sleeping fish called Devil-whales that swallow ships whole. When early mapmakers set about to chart the Atlantic, they turned to these tales with little else to go on. For this reason, early maps are littered with half real, half imagined places.
Over the centuries, the legends of different seafarers mixed and mingled, so the exact source of these legendary islands are impossible to disentangle. But what seems clear from all these stories is that though people didn’t know exactly what was out there, they had a vague notion of “far western lands”, which gives us reason to think people had been exploring the Atlantic long before we traditionally believe.
It's possible that the sea lore of the Atlantic is built upon thousands of years of actual geographical exploration, of source maps and oral history passed down from sailor to sailor through the ages. There is a lot of fantasy mixed into these tales. They are traveler’s tales, synonymous with exaggerated accounts, but, as was the case with Vinland, we are now discovering that some of these legendary places were more real than imagined.