Conceived exclusively for football, the stadium consists of a double bowl of terraces with superimposed access ramps that wind round it completely.   The enlargement works for the World Cup included a third ring of the upper bowl, supported by eleven stair towers on three of the four open sides of the structure.
   The four corner towers, like the ones containing lifts and facilities, support a powerful covering of steel and transparent polycarbonate, allowing a total protection of the terraces.