This is worth seeing if you are staying in Milan. It is quite a building. Watch your wallets and purses, though. And beware of the street people who start off by giving "free" welcome gifts. They are after money, just cut them off. Milan should do something about the numbers of flower sellers, too. After ten or twelve, it gets annoying.
If you own or manage Duomo Square, register now for free tools to enhance your listing, attract new reviews, and respond to reviewers.