If you are a sucker for those books that hypothesize that Earth was visited by extra-terrestrials in the distant past, then this is the site for you. One artifact that is brought up in nearly all of them is The Piri Reis Map, a document that seems to be a map includes parts of the world (such as Antarctica's ice-covered mountains) that were thought to be very recent discoveries. But, are they a hoax? Personally, I love all this stuff even if I don't want to believe it!
http://www.world-mysteries.com/sar_1.htm