What helped Romans to build their massive structures was concrete. They developed it around 1st Century BC.
Concrete can be seen for example in the famous Panthenon.
The Romans built massive structures using concrete, which they perfected by mixing water, lime, and volcanic ash around the 3rd century BCE. This innovation allowed them to create durable and impressive architectural forms like the Pantheon. Their advancements in construction techniques have had a lasting impact on architecture throughout history.
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