The beauty of San Sebastián is largely due to its environment, to its landscape. Few cities are endowed with more favorable natural conditions. The site of the Kursaal auditorium and congress centre at the mouth of the Urumea river is a geographical accident and must remain as such. Hence the architect proposed to erect a building that would not violate the presence of the river in the city. The auditorium and the congress hall, the key programmatic elements of the scheme, are conceived as separate autonomous volumes, as two gigantic rocks stranded at the mouth of the river forming part of the landscape rather than belonging to the city. All other facilities – the exhibition halls, meeting rooms, offices, a restaurant, and musicians’ services are located in the platform at the base of these cubes.

The auditorium contained within the larger of the two prismatic volumes measures approximately 65 by 46 by 22 metres and celebrates its character of quasi-geographical accident with a slight inclination towards the sea. The volume of the 1,828-seat auditorium is inscribed asymmetrically inside the glass prism, seeming to float within it. The asymmetry is oriented in such a way that a visitor entering the foyer is unconsciously led towards the highest level where the mount Urgull and the sea in all its splendor can be contemplated from a singular window. This window punctures the building’s double wall, composed of a steel skeleton clad inside and out with special, laminated glass elements. The result is a neutral and luminous interior space whose only contact with the outside world is through the foyer window. Outside, the glass surfaces protect against salt-laden winds from the sea, making the volume a dense, opaque, yet changing mass by day, and a mysterious and dazzling source of light by night.

The rectangular hall adheres to the formula deemed best by acoustical specialists, with dimensions nearly that of a square in terms of its length to width ratio, a flat ceiling and a height providing for a volume of approximately 10 cubic metres per spectator. The continuity and free-standing condition of the hall make it possible for patrons to reach all areas from any of the doors.

Similar design and structural criteria have been used in planning the smaller congress hall, which is also inscribed in an inclined prism measuring 43 by 32 by 20 metres. The asymmetry here is less evident, but the view from the foyer of mount Ulía and the sea in the background is just as spectacular.

The open space of the platform below provides entrances to the auditorium and congress hall, information and ticket booths, and access to a 500-car parking structure. This plinth serves as the meeting space between the cultural centre and the city, opening onto the Avenida de la Zurriola, and providing a wide outdoor space for public access. In this manner the new cultural centre is intended to be a significant urban episode in what has always been a breathtakingly beautiful stretch between mount Ulía and mount Igueldo.