The Da Vinci Code WebQuests

Though the official "prize" was given out at that time, the web versions of the quests were never closed, and have remained active ever since.

The original version involved deciphering a series of cryptic clues at the publisher's website.

Those wishing to solve the quests were required to examine the U.S. version of the book's dustcover jacket, and to search the web to learn the answers to certain questions or clues.

All those who successfully completed all 24 puzzles before the closing date for that country were entered in a prize draw with prizes ranging from a set of Da Vinci Code Top Trumps cards to illustrated copies of The Da Vinci Code.

Participants were invited to "board the Eurostar", taking them through various destinations in Paris and London, encountering riddles, puzzles and hidden clues scattered across both cities.