Was the New World "discovered" by Europeans before Columbus?

And continuing on my thread today of ancient maps, the topic of North American discovery prior to Columbus has always a fun subject to explore.

For your consideration:
The Vinland Map: According to our friends at Wikipedia, radiocarbon dating of this map dates back to 1423-1445 and shows Greenland in surprising detail. I personally believe that the evidence of L'Anse aux Meadows is strong evidence our Norse brethren were here before Columbus.

The Piri Reis Map: aguably this map was created past 1492 (approximately 1513) but it shows detail of areas of South America that had supposeldy not yet been explored.

For your Reading Pleasure:
Vinland Map:
. http://www.bnl.gov/bnlweb/pubaf/pr/2002/bnlpr072902a.htm
. http://en.wikipedia.org/wiki/Vinland_map

Piri Reis Map:
. http://en.wikipedia.org/wiki/Piri_Reis_map

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