Austrian National Library — Prunksaal (State Hall)

The Prunksaal, or State Hall, of the Austrian National Library was built between 1723 and 1726 by Johann Bernhard Fischer von Erlach and completed after his death by his son Joseph Emanuel, commissioned by Emperor Charles VI as a suitably magnificent home for the imperial court library. At roughly 80 metres long and 20 metres high, it remains one of the largest and most opulent historic library halls anywhere in the world, its central oval dome covered by Daniel Gran's 1730 fresco depicting the apotheosis of Charles VI as founder of the library.

Below the fresco, dark wooden shelving holds around 200,000 books dating from the early 1500s through the mid-19th century, organised beneath marble statues of Habsburg rulers and populated with antique globes original to the room — a working research library reading room turned into one of Europe's most visited library interiors purely on the strength of its architecture.