The vault relies on the architectural principles that guided the construction of ancient Roman buildings, such as a 33-acre public bathhouse in central Rome that still stands today.

The oldest record of barrel vaults is estimated to date back to 4000 BC. These provided the spans in the Sumerian ziggurat at Nippur in Babylonia, built from fired bricks amalgamated with clay mortar.

ROME, Sept 3 (Reuters) - The Arch of Constantine, a giant ancient Roman arch next to the Colosseum, was damaged after a violent storm hit Rome, conservation authorities said on Tuesday.

Braving bitter cold and wind, archaeologists in Serbia surveyed the site of an ancient Roman triumphal arch, one of only a handful in the Balkans, that dates back to the third century.