[Tallguy]

That was most likely the Map of Piri Riis.

...which is a forgery.

[Pharmboy]

I've looked around a bit about the Piri Reis Map and couldn't find anything about it being a forgery (although it may be). At any rate, I found this, which seems pretty thorough. Do you have another site that shows it to be a forgery?

[Swordmaker]

That was most likely the Map of Piri Riis. ...which is a forgery.

That is the claim of some... but others with as much or more expertise disagree.

As with the Vinland map, the finding of Anatase by microscopist Walter C. McCrone was the start of the claims of "FAKE!" but many older manuscripts have now been found to contain Anatase... so, unless we agree that all those other manuscripts of known provenance are also frauds, the question of the authenticity of both the Vinland Map and the Piri Re'is map are back up in the air.

I recall reading one report on the Vinland Map where the author claimed to have found the source of the parchment... by matching worm holes... in the end pages of another manuscript... which, if true, would put IT back in the realm of fake.