Hey, Boss, wrap-your-noggin around THIS, Dude!!! The Pantheon had NO "rebar" in it of ANY kind!! "There's no rebar in there. That makes it the single largest unreinforced, concrete dome in the entire world. And, yes, it was built by the Romans in 125 A.D., not by later architects." https://www.google.com/search?q=did+the+pantheon+have+rebar+in+it&sca_esv=601452934&source=hp&ei=-qyyZbvTCIrKkPIP0ZalwAg&iflsig=ANes7DEAAAAAZbK7ClvY1M4SV1dKW6d2dqoEEfse5NRq&oq=did+the+pantheon+have+rebar&gs_lp=Egdnd3Mtd2l6IhtkaWQgdGhlIHBhbnRoZW9uIGhhdmUgcmViYXIqAggAMgUQIRigAUj9hQFQAFiBb3AIeACQAQCYAbgCoAGBFaoBCDMxLjIuMS4xuAEByAEA-AEBwgIREC4YgAQYsQMYgwEYxwEY0QPCAgUQABiABMICDhAuGIAEGIoFGLEDGIMBwgILEAAYgAQYsQMYgwHCAg4QLhiABBixAxjHARjRA8ICDhAAGIAEGIoFGLEDGIMBwgIIEAAYgAQYsQPCAgsQLhiABBjHARjRA8ICCBAuGIAEGLEDwgIOEC4YgAQYxwEYrwEYjgXCAgsQLhiABBixAxiDAcICCBAuGIAEGNQCwgIEEAAYA8ICBxAAGIAEGArCAgYQABgWGB7CAggQABgWGB4YCsICCxAAGIAEGIoFGIYDwgIFECEYqwLCAgUQIRifBcICCBAAGIAEGKIEwgIIEAAYiQUYogTCAggQABgWGB4YDw&sclient=gws-wiz