Most likely it was not (just) supreme architectural skills and good fortune that made the Trajan Forum last for almost 20 centuries, but volcanic ashes in the mortar used by the ancient Roman builders. X-ray analysis of a wall sample from the Trajan's Market ruins in Rome showed that the mortars used by ancient Romans contained stratlingite, a mineral known to strengthen modern cements.
The cement used by Apollodorus of Damuscus' builders to construct the huge ancient roman complex contained sandy ash of a volcano that erupted 456,000 years ago.
