Reading Room
I was there once a few years ago. It's absolutely breathtaking to step in there.
The Reading Room of the British Museum is situated in the center of the Great Court. It used to be the main reading room of the British Library, but that relocated to the new British Library building at St Pancras, London. The old Reading Room was opened to the public in 2000, following a renovation by noted architect Sir Norman Foster. It contains a collection of books on history, art, travel, and other subjects relevant to the British Museum's collections, on open shelves.
Sshhht... reading in progress...