Vaulted Halls of the Domus Aurea, Nero's Golden House in Rome
Concrete vaulting in the surviving wing of Nero's Golden House on the Oppian Hill. The palace was raised on ground cleared by the fire of 64 AD, and its engineering — brick-faced concrete spanning rooms without timber — is the same technology the emperor imposed on the rebuilt city around it.
The Domus Aurea is remembered as a scandal: an emperor taking the burnt centre of his capital for a private park. It is also the best surviving evidence of what Nero's builders could do. The vaults here carry their loads in brick-faced concrete rather than wooden beams, and the same principle runs through the building regulations Tacitus records for the rebuilt city — wider streets, height limits, party walls of solid stone, porticoes at the owner's expense, and a ban on shared timber structures. The palace was buried within decades; the rules outlasted it. See how Nero rebuilt Rome as a fireproof city.
CC BY-SA 2.0 — source (Wikimedia Commons). Free to reuse under the stated licence.
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