Porta Sempione ("Simplon Gate") is a city gate of Milan, Italy. The name is used both to refer to the gate proper and to the surrounding district (quartiere), a part of the Zone 1 division (the historic city centre), including the major avenue of . The gate is marked by a landmark triumphal arch called Arco della Pace ("Arch of Peace"), dating back to the 19th century, although its origins can be traced back to a gate of the Roman walls of Milan.