Built under Emperor Aurelian between 271 and 275 AD, the Aurelian Walls enclosed the enlarged city of Rome with a roughly 19-kilometre circuit that included the seven hills, the Campus Martius, and Trastevere. Raised during the third-century crisis after invasions and unrest exposed Rome’s vulnerability, they were an emergency defense and a statement of continuing imperial power. Constructed quickly by citizens in brick-faced concrete and incorporating existing monuments, the walls were later strengthened and heightened. They remained an important military boundary for centuries, helping protect Rome through medieval attacks and still shaping the city until the breach at Porta Pia in 1870.

Photo: Wikipedia · Public domain

Photo: Wikipedia · Public domain

Photo: Wikipedia · Public domain

Photo: Wikipedia · Public domain

Photo: Wikipedia · Public domain