As Nichole Doub -- Head Conservator at the Maryland Archaeological Conservation Laboratory -- was helping extract the remains of an 18th century ship from the mud of the World Trade Center construction site, she was asked a familiar question:

Lucky coin? Ever since the 2nd century B.C. -- not long after Romans began minting coins -- shipbuilders have been slipping a coin into the structure of their ships. It's a tradition that continues today. In fact, the USS New York - made partially from steel recovered from the World Trade Center towers - did it as well.

For the ancient Romans it was likely a continuation of religious customs. Now it's just a tradition and done for good luck.

Here's what they found:

I wasn't so sure I wanted to publish this, since the coin is so butt-ugly and virtually unidentifiable. Tim adds:

To read the complete article, see:WTC Ship Gives Up Lucky Coin(news.discovery.com/archaeology/wtc-ship-gives-up-lucky-coin.html)