The project built at the Ebert Park occupies a rectangular site. A main feature of its central nucleus is a square hall, of 60 by 60 m area, which can house 2400 seated spectators. The shell roof of this ball is outstanding. It is a hyperbolic parabolid, which covers a large area with a minimum of material. Another noteworthy feature is the strong and harmonious design of this hall, which consists essentially of a monolithic rcjof, made of precast parts, and a powerful prestressed boundary girder resting oh piles, which take up the vertical loads, whilst a great prestressed concrete, tie member, of 110 m length, reacts the horizontal thrust component of the roof loads.