Imperial Treasury Vienna
The Imperial Treasury (German: Kaiserliche Schatzkammer) at the Hofburg Palace in Vienna, Austria contains a valuable collection of secular and ecclesiastical treasures covering over a thousand years of European history.
Why? Because only there you can admire the crown of the emperors of the Holy Roman Empire or the Agate bowl that was belived to be the Holy Grail.
If you like "treasures", emporerstories, invaluable relicts and items, you really have to go there.