The Vatican Secret Archives is one of the grandest historical collections in the world. It’s also one of the most useless. The grandeur is obvious. Located within the Vatican’s walls, next door to the Apostolic Library and just north of the Sistine Chapel, the VSA houses 53 linear miles of shelving dating back more than 12 centuries. It includes gems like the papal bull that excommunicated Martin Luther and the pleas for help that Mary Queen of Scots sent to Pope Sixtus V before her execution. In size and scope, the collection is almost peerless. That said, the VSA isn’t much use to modern scholars, because it’s so inaccessible.