Gavin Menzies has a number of dubious hypotheses about historical events. One is that the Chinese explored large parts of the world in the fifteenth century. He suggests that Ferdinand Magellan, Vasco da Gama, Christopher Columbus, and others followed Chinese maps. Others have taken Menzies’ idea and run with it.
In 2006, Paul Chiasson published a book, Island of the Seven Cities, explaining how the Chinese settled in Nova Scotia in 1421. As evidence, he shows an aerial photograph that he says was taken in the 1920s, showing traces of roads and foundations.
This web site, The ‘1421’ Myth Exposed, takes on those myths.
In this section, Island of the Seven Cities Exposed, Andrew Hanam thoroughly debunks that claim with a series of properly dated photos. The archaelogical evidence cited by Chiasson turns out to be modern firebreaks and drilling sites.
Other sections of The ‘1421’ Myth Exposed debunk the Chinese discovery of Australia, the massive size of Chinese junks suggested for oceanic voyages, and a “1418 map” that was produced within the last fifty years.