The Pantheon, Rome — built in 125 AD and still standing. This is what it may have looked like in Roman times. That grey concrete dome you see when you visit today? The leading theory among archaeologists is that it was originally painted deep midnight blue, with gilded bronze stars in every single one of those 140 coffered panels — representing the night sky and the cosmos. The oculus at the top was the sun. The whole building was essentially a model of the universe. Add in fully painted and gil