There is the answer........
The answer is concrete.
<span>The Romans' ingenious use of concrete was
instrumental in the construction of the great cathedrals of Europe 1,000 years
later. Vaulting of concrete completed the building of the great cathedrals and amphitheater
of the Romans. It also made the Pantheon dome and the Palestrina’s Sanctuary of
Fortuna Primigenia. </span>
