system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why did entire ancient mega-important complexes like the Roman Forum fall into such neglect and disrepair, while others like the Pantheon remain in such good condition?
gpt
With no disrespect for the other comments, which are both true, often the distinction between what was torn down and what was kept was whether or not they were repurposed. In your example, the Pantheon (despite it's name) became a Christian place of worship. The forum didn't really (apart from a couple of spots, like the Mamertine Prison). Similarly, Hagia Sophia is in tremendous shape, mainly because it became a mosque instead of being destroyed in war. The theatre of Marcellus in Rome became palazzi and although large chunks are missing, it is still in better shape than many ruins and has people living in it to this day.