Football is a popular pastime among many of the city's citizens, as Buenos Aires, featuring no fewer than 24 professional teams, has the highest concentration of teams of any city in the world. with many of its teams playing in the major league. The best-known rivalry is the one between Boca Juniors and River Plate, the match is better known as Superclásico. Watching a match between these two teams was deemed one of the "50 sporting things you must do before you die" by ''The Observer''. 