If you go in Cordoba ( Spain) there is a beautiful bridge over the Guadalchivir river build by the Romans still in use today with daily traffic passing over , including trucks and so in Rome and in other many European city.

About the Mediterranean clime: Italy have a very extreme climate change during the seasons, forget about the really hot summer that last few months, winter is extreme too when the majority of the country is covered by a thick lay of snow and temperature way below zero.