The interior didn't survive unscathed. The design of the upper walls was "fixed" during the renaissance, with one small section now restored to something more l

The interior didn't survive unscathed. The design of the upper walls was "fixed" during the renaissance, with one small section now restored to something more like its original design (based on paintings of the original, see top right of photo): https://userscontent2.emaze.com/images/9fd064fa-8fb9-409b-acbf-590b16c8adcb/33570d86-ed8e-4a7c-a67c-89f8b4306f0e.jpg https://userscontent2.emaze.com/images/9fd064fa-8fb9-409b-ac... Additionally, Pope Urban VIII had the bronze ceiling of the portico melted down to make cannons in the 1600's. On the left side of the portico, you'll also notice that some of the columns don't match. If I'm remembering right, these were taken from a nearby Roman bath complex to repair earthquake damage to the portico. https://upload.wikimedia.org/wikipedia/commons/3/35/Pantheon,_portico_01.JPG https://upload.wikimedia.org/wikipedia/commons/3/35/Pantheon... All that said, it's still in remarkably good condition for being close to 2000 years old.