Karlskirche / Vienna
I still have to laugh about the time someone posted a picture of the church (foundation stone laid in 1716) with the caption "They're building a mosque right now in the middle of Vienna," and all the stupid rassists / Nazis fell for it.
It’s pretty embarrassing when you’re so far right that, while "protecting" the Fatherland and Christianity, you mistake a Christian church for a mosque ;)