São Paulo Museum of Art (MASP)

Lina Bo Bardi, 1968. The museum on Avenida Paulista hangs its glass-and-concrete gallery box from two enormous prestressed beams carried by four red pillars, leaving a 74-meter span of open ground underneath, as this view shows. The land came with a condition that the view across the city be kept open, and Bo Bardi made the ground beneath a covered public square, used for markets, concerts and protests. Inaugurated in November 1968, it is the clearest case of brutalism's heavy engineering put to work for the street.