I've been to Mexico and almost every temple is held together with a concrete-like substance that has survived thousands of years. I've been told that it has lava rock in it, possibly replacing granite in normal concrete.

Here is a happy couple Link on top of the Sun Temple in Mexico (just outside la Ciudad Mexico) and you can see the concrete at their feet.

This example in Cholula predates the Roman occupation/conquest of Euorpe by a few years and was done completely independently of any contact with the Romans. IOW, the is no way whatsoever that the people of Cholula knew the Romans and could have learned it from them.

So why is credit given to the Romans when the Aztecs had no contact with them and there are some temples in Mexico that date back to 600 BC (long before the Romans)?