The Plaza Constitución is the central travel hub for trains, buses and cabs in the south of Buenos Aires. This makes it one of the busiest areas if suburban traffic is concerned. Everywhere you see Argentineans catching one of the various commuter buses to get into the city's center or to their homes in the suburbs. The pink building is the train and underground station Constitución. It was built in the late 19th century to cope with the increasing suburban traffic due to rising immigration. From here you can travel further south by train to destinations like Mar del Plata and Bahia Blanca, for instance. At day the area is insanely crowded, loud, and at least to some extent chaotic. At night this place is best avoided.