 Later the Aurelian Wall replaced it, enclosing an expanded city, and using more sophisticated designs, with small forts at intervals.The Romans walled major cities and towns in areas they saw as vulnerable, and parts of many walls remain incorporated in later defensive fortifications, as at Córdoba (2nd century BC), Chester (earth and wood in the 70s AD, stone from c. 100), and York (from 70s AD).Strategic walls across open country were far rarer, and Hadrian's Wall (from 122) and the Antonine Wall (from 142, abandoned only 8 years after completion) are the most significant examples, both on the Pictish frontier of Roman Britain...

On his return from campaigns in Greece, the general Sulla brought back what is probably the most well-known element of the early imperial period, the mosaic, a decoration made of colourful chips of stone inserted into cement.