“The Greeks knew about this place long before the Romans ever got there.”
And probably the Phoenicians before the Greeks.
It was not unusual for the Romans to worship local Gods and incorporate them into their Pantheon. Pagans were much more ecumenical than Judaeo-Christians. Aquae Sulis
is an example of Romans incorporating a local deity into their Pantheon by identifying her with a Roman goddess.
The Monolith builders antedated the Romans, Greeks, Phoenicians and Celts.
Megalith, not Monolith - brain burp.
Actually the Greeks go way before the Phoenicians to the second millennium BC - for example Mycenae-—some ruins found in Sicily quite recently were constructed by Phoenicians and are of the 8th century BC.