Its a very interesting story:

Video info:
Researcher Charlotte Harris Rees discussed Asian maps dating as far back as 4,000 years ago that show the coastlines of the Americas.

Picking up on the work of her father who collected these maps, she suggested that the ancient Chinese were seafaring and traveled to America far before Columbus' arrival. As further evidence, she cited genetic markers (DNA) that are shared only by Asians and Native Americans.

“This is a great time to rethink history and to step into the thrill of discovery” says Rees.

This site trying to debunk the map. What do you think of the debunk?