The ancient Greeks could have reached Canada in 56 AD - almost a millennium before the Vikings.
This is according to a controversial study that claims Hellenistic Greeks had such detailed knowledge of astronomy that they were able to pinpoint Atlantic currents that would propel them west.
This idea is based on a study of the text 'De Facie' by Greek biographer and essayist Plutarch, who lived between 46 and 119 AD.
A character in the texts recounts meeting a Greek stranger who had recently returned from a 'great continent' - and scientists say this may have been Canada.
Powered by sails and oars, they may have regularly visited Newfoundland, mined gold and set up colonies that thrived for centuries, the study claims.
However, there is no concrete evidence of these trips and many historians and maritime archaeologists have dismissed the work as 'unfounded'.
'Our intention is to prove, with modern science, that it was possible for this trip to be made,' Ioannis Liritzis, an archaeologist from the University of the Aegean told Hakai Magazine as part of an in-depth feature on his research.
These early settlers may have travelled for the sake of finding new lands or riches, researchers say.
They believe some travellers would return home after a brief stay but for others the trip was one way.
Researchers acknowledge that they do not have evidence that these trips were made but believe they were possible, as suggested by the writings of Plutarch.
Plutarch wrote more than sixty in-depth biographies of famous Romans and Greeks, detailed in his writings of Parallel Lives.
This theory is based on evidence from Plutarch's work De Facie, also known as On the Face Which Appears in the Orb of the Moon.
In this work, which became familiar to classicists during the Renaissance, characters discuss whether the moon is another Earth, whether it has life, and other philosophical questions.
One character recounts meeting a stranger who had recently returned from a 'great continent'.
The first Western civilisation known to have developed the art of navigation at sea were the Phoenicians, around 4,000 years ago in 2,000 BC.
Phoenician sailors navigated using primitive charts and observations of the sun and stars to determine directions.
It would take many centuries before global navigation at sea became possible.
By the second millennium BC, accumulated knowledge of stars and constellations began to facilitate more direct travel across the Mediterranean.
As increasing knowledge of astronomy began to spread and became more precise, navigation across open water became more possible and less risky.
Detailed knowledge of the constellations, eclipses, and moon movements made navigation during day and night much easier.
Other developments include the use of sounding weights, which helped sailors determine the depth of water in given locations.
Weights would be lowered from a boat and would inform on the location’s depth.
This knowledge could help with regards to how far ships were from land, as shallower seas could indicate that land was nearby or approaching.
By the late first millennium BC, new developments facilitated further navigation capabilities.
This included the development of navigational charts and information passed down to sailors.
These charts include types of notes and descriptions that likely assisted sailors over generations.
Farther ventures were enabled by the development of scientifically and mathematically based methods and tools.
It seems the Ancient Greeks did develop early incarnations of these instruments, perhaps including the Antikythera mechanism.
Found in 1900 near the Greek island of Antikythera, this metal contraption appears to be a mechanical device with gears and wheels.
Some experts believe it may have been used to aid navigation and understand the movements of celestial bodies in the third or second century BC.
Dr Liritzis and his colleagues believe this content was in fact North America, specifically Newfoundland.
This is not the first time that this theory has been proposed.
Johannes Kepler, a German mathematician and astronomer who was a key figure in the 17th-century scientific revolution, also believed that this reference was in relation to North America.
The stranger recounts how travellers made the trip every 30 years when Saturn appeared in the constellation Taurus.
The ancient Greeks closely followed astronomical phenomena associated with Saturn, which was called Kronos at the time.
The suggestion is these trips could have occurred every 30 years for centuries.
Unfortunately the first few chapters of De Facie have been lost so no one knows on what date these conversations happened so researchers had to date the story themselves.read more