The Park is located in a large green space in the heart of Milan, open since 2004, show the historical and archaeological wealth of a district of the ancient Mediolanum-Ticinum. The Archaeological Park preserves a portion of the foundations of the Roman amphitheater (I-IV century AD). The theater was built in the Augustan period (late first century BC - early first century AD) in the western sector of the city, near the walls and the Porta Vercellina. The remains came to light as a result of work for the construction of buildings in the area. The most important discoveries occurred between the late nineteenth and early twentieth century during the construction of the current headquarters of the Chamber of Commerce and the Milan Stock Exchange. The conserved structures permit the conclusion that it was a building to show the most relevant of the Cisalpine. The space of the bleachers for spectators (the auditorium) was semi-circular and had a diameter of 95 m; outside it appeared with a curved front, high about 20 m, with two rows of arches on pillars and with a probable penthouse crown, made with blocks of strain Adda.