Bibliotheque Nationale is about the Books.

The scheme of this building is simple, yet elegant: four glass corner towers bracket an esplanade which in turn frames an immense interior courtyard. Public spaces and reading rooms are organized below the esplanade, affording views into the natural, meditative space of the courtyard garden.

 Windows to the library's book collection...

Windows to the library's book collection...

 ...didn't work well with sunlight.

...didn't work well with sunlight.

Visitors are typically not admitted into the towers, which are mostly dedicated to storing books. The architect’s original vision was that this would provide a striking portrayal of the library’s growing collection; however, sunlight protection requires the books to be hidden from view.

 Corner towers framing the interior courtyard

Corner towers framing the interior courtyard

Find more photos of Paris's Bibliotheque Nationale here...