By night the four buildings are surrounded by a halo of light coming from inside and culminating at the top of each building, as if they were lighthouses. The result is an enchanting scenario, as light is diffused in the square below while the towers are reflected in the waters of the Seine.
Across from the square is a huge garden, where an atmosphere of silence and serenity dominates, giving the visitor the sensation of being suspended in time. Inside the building one room follows upon another, like a series of stage sets, each with its own strong identity, creating a strong impression in the visitor's mind.
There is a reading room open to the public containing 1600 seats and another one reserved for scientists and researchers with over 2000 seats.