Built in the first century AD Arena di Verona was the third largest amphitheatre in the empire.  It used to hold 30,000 people when it was completed.  Today Arena di Verona is a great venue for many concerts and performances from the likes of  Muse, Radiohead, The Pink Floyd and many others.  There are also opera performances which with the exception of the two wars have been showcased at the arena continuously for the past 100 years.