The Roman "Church," now of course demoted to the status of just another denomination, desecrated a lot of buildings in Rome for their own purposes. Part and parcel of the long term strategy of gaining paying adherents by adopting a good deal of the pagan religions that went before: a pantheon of lesser gods ("saints") that could be prayed to, given emoluments, and so on; adopting pagan holidays (Christmas, Easter) on the same schedule but with new or at least ammended significance; worship of an "earth mother" or otherwise powerful female goddess and, of course, appropriating the old places of worship or veneration as churches. But the item here is not religion at all, it is engineering, and the point I was trying to make in the first place: bricks and mortar, not marble, were the fabric of many long lasting Roman structures, and among them are marvels of engineering that have proven the skills of the constructors through the test of time. I have no idea whether or not the Roman engineers had the calculations that would today be commonplace in the design of the buildings they erected, but they had at least an intuitive knowledge of what worked. Sorry if I offend you by revealing my disgust with organized religion, especially those sects with feudal heirarchies. Maybe that has clouded the discussion, but so be it.

Have you ever wondered why there are what appear to be steps around the base of the dome of the Pantheon? Ask, and it shall be revealed!