Though [Marco] Polo himself states frankly that he has never visited Japan -- and thus that what he has to say about it is second-hand and perhaps inaccurate -- the notion of the mysterious island kingdom of Cipango that he planted in European consciousness at the end of the thirteenth century was later one of several powerful influences that spurred Christopher Columbus forward in his crossings of the Atlantic at the end of the fifteenth century. This was so because Columbus -- underestimating the circumference of the earth and knowing nothing of the existence of the Americas or of the Pacific Ocean -- believed that he could reach Cipango, and thence the Chinese mainland beyond, by sailing directly westwards across the Atlantic from Europe. Columbus is also likely to have calculated that Cipango would be reached after only a relatively journey towards the west -- for he had read Marco Polo, who describes Cipango, erroneously, as lying 'far out to sea' fully 1500 miles to the east of the Chinese mainland (the true distance is nowhere much more than 500 miles).