Like a modern acropolis, concept for the new National Stadium of Japan places the arena on a plinth as a sign in the centre of the city. A large plaza is created by the plinth forming the main public entryway. The seating tribunes are conceived as landscape elements of the podium, and are covered by a light, shell-like roof touching the ground at only four points. The shell is topped by a retractable photo-voltaic glass roof element that separates into two visible wing-shaped leaves opening the stadium to the sky.