A multi-cache located at the British Library. Entry to the building is free of charge and you do not need to go into any temporary exhibitions or Reading Rooms to complete the find.
Please do not ask Security or the Information Desk for assistance. They are aware of the cache and it is placed with permission from the Library, but it was not placed by anyone at the Library, so they can't help (plus that would totally defeat the purpose! ;) ).
The container is not at the listed coordinates, but use the clues to get the coordinates of N51 GH.CAI W000 DB.EJF.
Once at that location, you will find a small container with directions back into the Library to find the final cache. Leave enough time to enter the building before it closes to sign the final log book!
The final container is quite large (5 gallon) and can hold many swaps and travelbugs.
Congrats to arewethereyet?? for the First to Find on 27 January 2011!
Opening hours limited and can be found at Opening Hours. Generally the Library is open until 6pm, but please be aware you cannot access all the required areas on a Sunday or Bank Holidays.
Do not bring luggage as the Library will not let you in with anything larger than hand luggage and all luggage is subject to search - and usually they exercise this right!
Outside in the piazza, there is a statue of Newton. The last number on the plaque will give you A.
Inside now to the Foyer, where you will see a statue of Shakespeare. The third number in the year the statue was bequeathed to the British Museum is B. If you haven't figured out what B obviously is, and can't see the information about the bust due to exhibition hoarding, then B is also: The last number of the year that you can see engraved on the stone, minus 1.
Down to the Lower Ground floor now and you'll find a piece of art called "Paradoxymoron". A certain Gallery helped support this gift to the Library - take the number of letters in the second word of that Gallery name for C.
Find the large model of the Library and count the number of trees and take away 5 to get D.
Now head into the Sir John Ritblat Gallery. Find the free-standing large globe, and on it you'll see the name of the donor. Add up the number of letters in the surname and you'll have E. This globe is currently not on display - the answer is 6. But please do come to the Gallery - it's the jewel in the crown!
You'll have noticed the glass-enclosed King's Library. Which King George donated these books upon his father's death with the condition that the books be "entire, and separate from the rest of the Library… in a repository to be appropriated exclusively for that purpose." F. (Tip - If you can't find it on Google, there is a bust of the king whose books these are in the Foyer - and his son is the George after him.)
Out now to the Conservation Centre. You can see the answer through the glass or you can go inside to look at the small display there. How many letters in the first word in the name of the contributor on the bottom left of the sign inside the Centre? This is G.
In the entrance to the Manuscripts Reading Room, there is a painting of Robert Harley. What's the first number on the plaque? This will give you H.
In front of the Newsroom, there is a bust of the moustached John Lawrence. How many times does the letter "N" appear on the plaque? This is I.
Your final stop is the Maps Reading Room foyer. How many letters in the first word of the name of the very large atlas across from the lift (see the small brass plaque on top)? Now you know J.
Now to go outside to find the next stage, which will lead you to where the final is held (back in the Library).
The final is also a Book Crossing location (see http://www.bookcrossing.com/ for more info). When releasing books, go to United Kingom:Greater London:-- Geocaches -- and the cache name will come up in the final Crossing Zones section.
Proud two-time Geocache of the Week recipient! 
Winner of Best Cache in England and Best Multi-Cache at the 2017 British & Irish National Geocaching Awards! 