Rome

Yes, there's a tremendous danger to taking hormonal teenagers to Rome -- Rome is sexy, has been ever since the Etruscans moved in some 3,000 years ago. Sexy design, sexy art, sexy music, and, well…but listen, your kids will remember it. Is it so bad if they have a brief summer fling?

Well, aside all of that, Rome has amazing history -- the ancient stuff is still all around you, and it doesn't take a whole lot of imagination (and, again, a bit of research and prep work) to bring it all back to life. I mean, you can stand on the actual spot where Caesar was murdered -- that's a picture you can paint.

Technically, of course, this is not Rome -- but are you really not going to visit Vatican City? No matter your feelings on the Papacy, this small patch of land and collection of buildings does an amazing job of highlighting the critical contributions the Church has made to western art and culture. 

Flight options from the US into Rome aren't quite as good as Milan, but intra-Europe flights are cheap and plentiful. Feel free to hop over to Barcelona, Berlin, or Paris; or just drive north to get to Tuscany.