Monza is a city and comune on the River Lambro, a tributary of the River Po, in the Lombardy region of Italy, about 15 kilometres north-northeast of Milan. It is the capital of the province of Monza and Brianza. Monza is best known for its Grand Prix motor racing circuit, the Autodromo Nazionale di Monza, which hosts the Formula One Italian Grand Prix. On 11 June 2004, Monza was designated the capital of the new province of Monza and Brianza.