Even Older Rome

The Roman Forum is the area where Rome began - predating 700 BCE.  You see 'layers' of structures representing a thousand, and more, years of civilization.

Basilica in the background. Basilicas were for business transactions and were open to everyone. Temples were open only to the holy people/priests.  This basilica shows 3 domes - basis for future Christian churches like St Peter's, Blue Mosque (which was originally Christian cathedral in Constantinople. Emperor Constantine was first Christian emperor of Rome).

The oldest civilization lies many stories below what is now street level. Years upon years of buildings falling over or being damaged by fires and earthquakes resulted in newer buildings just built above them.  With the excavations that have uncovered the most ancient buildings, you can see an ancient temple with a christian church built on top of it, and modern street level even above that.
History is physically clear, showing that christian churches were built atop ancient temples. The only ancient temples that have survived somewhat in tact are those that were converted to churches - like the Pantheon. Only then were the structures cared for and refurbished over the centuries.

Christian fresco in ancient temple