Some examples:
The Greek Gymnasium.
The first public library in Rome was conceived of by Julius Caesar in
44 BCE. Caesar died before construction on his library could begin, but a number of subsequent emperors included the establishment of public libraries as part of their building programs, existing both in Rome proper and throughout the empire.
And from whence actually came the intellectual and in some instances, literally the architectural foundations of Christian basilicas. And these public spaces have earlier roots than Caracalla.
Everything after, including the gothic cathedrals are arguably repetitions on a theme.
If Godliness had continued to take second place to cleanliness...who knows how society might have developed in the west?
And of course:
The polytheism of the Roman Republic and some portions of the age of empire probably was an advantage.
You don't need a religious cult to achieve great spaces or buildings.
Okay, that's four ...
No, three: only adult male citizens (a minority of the population, as you know ) could use the gymnasium. And the remaining three are all from one place and era (a long era, granted).
And one could make an argument
(I'm not sure I would agree with it, but it could be made) that no great public gathering place built by the Roman Imperial regime was entirely areligious, since Emperors themselves were considered divine. I'd love to see Mary Beard weigh in on that.
Gladly agreed, as
I've already said:
I'm arguing that, as I said above, religion has, and has always had, enough redeeming characteristics that it doesn't deserve to be obliterated from the face of the Earth, as several of you here appear to be arguing.
That, and, as
@NotHardUp1 has pointed out, we have very few examples of human societies that have developed without religion, so a propensity for religion seems to be endemic to
Homo sapiens as a species, even if not to all individuals within that species.
And, as I've said, violence and oppression by the powerful also appear to be endemic to our species, and without religion, the powerful come up with other excuses to be violent and oppress.