The National Archives aka Public Records Office KEW 4k 

Public Record Office
National Archives
National Record Office
A Uk govt facility which gives limited access to declassified and "30 year rule" records. They are all stored UNDER this facility in a massive bunker. They get brought up for you to read upon request.
I thought this drone footage might come in useful to those doing research work on what this place does.
Music
Val_Holla by Audionautix