I’m currently wrapping up a trip touring many ancient monuments during winter (aka off-season), and nearly all of them were having some kind of renovation work

I’m currently wrapping up a trip touring many ancient monuments during winter (aka off-season), and nearly all of them were having some kind of renovation work being done. Usually it’s a combination of whatever ancient stone is left from antiquity, combined with new material of the same type that would have been used originally (though not in all cases, there is some form of “artificial stone” that is used at times, not sure of what that is). So, my guess at the answer to your question would be all of them, many times over.