[blam]

I saw the one hour special hosted by Graham Hancock on this subject. Interesting concept and I do believe some of the things he covers, such as, world wide travel in ancient times, etc.

[BradyLS]

Not quite the same thing, but you may wish to give Louis L'Amour's historical novel, The Walking Drum, a read. It's a real eye-opener on what people in Europe, Africa, and Asia knew or had known in the 12th Century.