National Library of Spain, Madrid

They do not allow foreign visitors in except for group visits (but the receptionist didn't specify how to sign up on group visit). Very disappointed

The largest collection in Spain, comparable in terms of on-site service to other large national collection in London and Paris. Off-site books can take forever to be delivered: order them before you travel. Don't expect the staff to speak much English. Anyone working on a topic with a Spanish angle to it should speak Spanish as well as they read it, and if you don't read it what are you doing here? The exhibitions are usually very good: to see them, take the ground-level entrance (rather than going up the stairs).

The beautiful entrance draws you into a fabulous building, a place where books send you back in a world without blemish.

The building, collection and staff are wonderful here. If you are not from Spain, all you need is a passport to obtain a Reader Card which allows you to look at books published after 1931. You cannot take the books out of this library, but you can reserve them for up to 15 days and read them in a beautiful and spacious room with plenty of desks, lights and free wifi.

Since I am a student at the Complutense University of Madrid I am often assigned to write papers on various subject that I sometimes just can't find anything about in my textbooks and the internet. I've came to the conclusion that the most reliable source of information in those situations is the Biblioteca Nacional de España. The staff there is very knowledgeable and quite helpful which saves me a lot of time browsing for the right book on my own.