But the past has just met the future.
Illustrated manuscripts representing a lifetime of work for a monk, documents written on animal skins, the first books ever printed, and millions of other pages and images are being scanned and digitized.
A joint venture between the Vatican and IBM will eventually make it all available to universities on a special Internet route.
"The main point is this, we don't want the treasure to remain hidden," says Archbishop Mejia, Librarian of the Holy Roman Church. "It's part of our mission to have the doors open."
Pope Nicholas V started the library before Columbus came to America. Donations from noble families and the spoils of legions sent forth by warrior Popes soon overwhelmed the original quarters, and forced expansion into many cramped chambers.
Scholars still are only allowed to see three documents a day.
"A large part of researching we've discovered is drudgery type of work involved in handwriting analysis to determine which monk wrote which part of which manuscript," says IBM's Vincent Yannuzzi, who has spent seven years setting up the digitizing program.
"We've pushed pattern recognition software technology to have a computer do that drudgery and free up more time for scholars to do intellectual work."
It will also make CD-ROMs available to allow ordinary people to tour the library.
The last wave of technology here was the invention of the printing press. Scholar monks of the time complained it would destroy their art.
Dom Ferigno, Prefect of the Vatican Library, says today's scholars welcome the computer revolution because it will provide intense and unlimited study time.
Scholars will be able to check into the world's oldest known cookbook -- with recipes from Roman times -- follow maps by Ptolemy, wonder at Aztec prints, and things not seen for centuries.
Will secrets be found?
"You never know, but it's always possible," says Archbishop Mejia.
With nearly half a million scholars and graduate students soon able to check in via computer, that may be an understatement.
Reported By Allen Pizzey
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