Known as the 'Big Eye', the Oita Stadium is one of the chosen venues for the next World Cup in 2002. It will be reused for the second stage of the Japan Inter-Prefectural Athletic Competition in 2008 after the World Cup, continuing to grow in the future to become a large-scale all-purpose sports park for Oita. The whole site covers an area of 225 ha and has several facilities outside the main football stadium. These include general fitness, training and lodging centres, a botanical pool, two multipurpose athletic fields, two rugby and soccer practise pitches, a softball field, tennis courts and other game areas. The main stadium features an open track for athletic events as well as the football pitch. It can also be used year-round for public events aided by its retractable roof. For soccer matches, spectator seats are placed right up to the edge of the pitch to bring them close to the action. To change over for track events a retractable seating system was developed. The stadium sits elegantly on its site, enhanced by the gentle curves of its spherical design. The choice of the sphere, Kurokawa says, is 'an expression of abstract symbolism'. This spherical shape also enables the retractable portion to move along its curved surface. The use of Teflon membrane panels with 25 percent light permeability obviates the need for artificial lighting during daylight hours. In order for the pitch to get proper exposure to sunlight the elliptical roof opening runs along the north-south axis. A main arch with perpendicular horizontal sub-members follows the elliptical shape of the roof opening. Between the roof and the spectator seating below the surrounding mountains can be seen from a slender ventilation clearstorey set just below the roof line. This slit of space is designed to create a feeling of openness inside the stadium. Since the original design, an idea emerged for a moving camera to be located on the main beam to deliver special dynamic images for television audiences around the world.