The Stramilano is an internationally-recognised running event held annually in spring. There are three distances: a half marathon with tens of thousands of competitors, a 10 km 'fun run' and the 5 km Stramilanina for junior competitors. Central Milan is closed to traffic for the event. Circumscribing the whole city, the half marathon starts at the Piazza Castello and finishes at the Arena Civica in Parco Sempione. Corso Sempione is a good vantage point from which to glimpse the runners whizzing past.