This gives some idea of the massive concrete structures that give the illusion of sails when the
Opera House is seen from across the water. Jorn Utzon's original drawings which won him the prize
of building the Opera House obviously were inspired by the idea of lightweight self-supporting shells.
Pier Nervi's for example. A great idea, but pure fantasy, and an approximation to Utzon's design
could be achieved only by this sort of engineering, and at enormous expense. Nice formwork, though.