You've just been unlucky then LM. All culture buildings are destroyed automatically, but other buildings have a chance of surviving. Wonders, shrines and academies are kept but no longer produce culture. The only time you can capture a city with a building that produces culture is when your UB produces culture when the normal building doesn't.
I vaguely remember that if you have the most culture in the city you are capturing then all the buildings are kept, but I'm not sure if this is actually true.
Actually, just click on the splash. The description will appear, overlaying the splash.When a wonder splash pops up, you don't have to wait until near the end, to find out the benefits of building that wonder. If you click on the bar next to the title of the wonder, and drag towards the middle of the splash, the cultural information and other benefits pop up. The wonder splash continues to run in the background. I found that out by accident today, don't know if that has been posted before...
Having defensive bonuses is one of their special features, Immortals can do it too.Just yesterday: Found out that Spain's Conquistadors can actually Fortify, and it's not a bug. -_-
oooh....That's true. Even foreign national wonders survive and the captured city has no turns to come out of resistance.
If a city containing max number of aircraft builds more planes, they are automatically rebased to the nearest safe location even if it is a fort. Apparently not a carrier, but a city or fort.