The change from the unroofed stadiums to sealed off buildings maybe the beginning that tickets were sought.

从露天场馆到封闭的建筑的，可能追求门收入的开始。

That must be the oval unroofed amphitheater in Rome. It was basically a stadium with comprehensive functions.

那马的椭圆型露天竞技场了，基本上综合功能的体育场。