The Pantheon, a temple to the gods, was completed in A. The temple's dome is still the largest unreinforced concrete dome in the worl.
Interesting article on composition of that nearly-indestructible ancient Roman concrete history buffs love so much. But, pretty photo, too! - Roman Temple in Pozzuoli, Bay of Naples, Italy
The core of this thick Roman wall was filled by one of their greatest innovations: concrete.
Why has Roman concrete lasted so long?
An impression of the pilot lagoon scheme in Swansea Bay (photo: Tidal Lagoon Power)
Old Roman buildings continue to survive after years, even though they are exposed to a variety of weather conditions.
Why Roman concrete still stands strong while modern version decays | Science | The Guardian