Pytheas and the Hyperboreans
A Greek navigator from the Greek colony of Massalia (today Marseilles) had circumnavigated Britain in the Fourth Century B.C., had "traveled all over it on foot" and had written a detailed account of his travels.
Furthermore, Pytheas reported sailing northwest of the British Isles for six days until "an ocean of slush ice and fog so thick one could not sail through" forced him to turn back.
During those six days, aided by the west-flowing off shore currents, could he have gone beyond Iceland to the shores of Greenland and the North Pole and met the "Hyperborean people"? (Inuits)