Not worth
Always wanted to go to an opera at La scala, but the arrogance of this place simply does not allow foreigners to attend that. For a purchase of a ticket you need to create and account, for that account you need to add your phone as verification and should receive a text message with code. And here is the trick, this is only possible for Italian phone number and nothing else. So forget to have a weekend in the city and visiting this place. They simply limit the ticket to Italian residents.