What material was the dome of Rome Pantheon made from?
The temple - 43 meter in diameter - was built by emperor Hadrian. Its dome with 8-meter wide oculus was built of unreinforced concrete that has been a mystery for ages. The weight of Roman concrete used to build the monolitic structure is merely 1/5 of common concrete. Such effect was achieved by mixing in of volcanic tuff and pumice.
reach: rather globalarchitecturehistory of architecturehistory of ItalyRome
Illustration: Gonzalo Malpartida