I watched visitors enter the State Hall of Austria's National Library for a minute or two. Their physical reactions to their first impressions were remarkably similar. Their eyes widened, their jaws dropped and a word like 'Wow' sneaked out in a whisper. Then their cameras came out. Mine did too.
The State Hall was designed by the famous Johann Bernhard Fischer von Erlach and the construction was supervised by his son, Joseph Emanuel in 1726.
The ceilings were the work of Daniel Grans and completed in 1730.