While it was difficult to leave all of my books alone in Pennsylvania for the summer, I suspect Oxford’s collection will suffice. Not only do I have access to the Lincoln College library (a gorgeous cathedral that has since been converted into an upper and lower-level reading room), but I also was officially sworn in to use the Bodleian Library. In order to use the library, you must be a university student or faculty member, and you must go through an induction process in which you read the following oath:
I hereby undertake not to remove from the Library, nor to mark, deface, or injure in any way, any volume, document or other object belonging to it or in its custody; not to bring into the Library, or kindle therein, any fire or flame, and not to smoke in the Library; and I promise to obey all rules of the Library.
The library is home to nearly 10 million volumes - so many that they actually keep most of the books in a storage facility and transport requested books to and from the library daily. The library is also the home to one of the original copies of the Magna Carta, one of the few remaining Gutenberg Bibles, Shakespeare’s First Folio, and numerous Biblical codexes dating back to 500CE. Another fun fact: parts of the Bodleian were used as Hogwarts Library in the Harry Potter films. I’ll be sure to look for the restricted section - just in case there are any extant Defense Against the Darks Arts books there.