My favorite (and one I personally witnessed when visiting East Berlin in 1980) is the “Fernsehtun Cross”. It is a TV tower that has what appears to be a cross on it when the sun shines, and the East Germans did everything they could to eliminate it, but they could not. https://mysticsciences.com/2016/12/18/the-story-of-the-fernsehturm-cross-the-popes-revenge/
This is a cool story. Never heard of it before!