porta san paolo, piazza ostiense, rome, italy

porta paolo piazza ostiense rome italy ancient city gate aurelian walls roman fortifications history pyramid cestius urban defense military architecture empire engineering historical landmark defensive 3rd century emperor district urbanism infrastructure medieval modifications road rome#39aph39#s gateways archaeological site ruins monument antiquity fortification system imperial protection landmarks classical transport routes strategic development planning fortified preservation cultural heritage relics entrance antiquities landscape historic paolo ostiense rome