The British Library

The national library of the United Kingdom, based in London. The library receives about 150 million samples written in all formats and known languages. On the shelves and rooms see books, newspapers, magazines, sound and music recordings, databases, stamps, maps, drawings etc.

One of the best libraries I have visited, but it's a pity that they don't let you into the room. You can only walk around inside the enclosure without going into a single room. If you are a librarian or you can change it, it will make a special visit.