We are about to visit a place few people have seen firsthand: the Vatican Library, a vast collection of historic treasures beyond compare. It was founded over five centuries ago, when Europe was coming out of the Dark Ages. It was a period of so-called humanism when the Catholic church was open to new ideas in philosophy, science and the human spirit.

It's the pope's library, but it contains much more than just church documents. There are manuscripts going back nearly 2,000 years on music and math, warfare and exploration - even cookbooks and love letters. The library is closed to the public, as it is a place for scholars only.