The Caisse d'Épargne building in Vienna, designed by architect Otto Wagner, is an iconic example of Viennese Art Nouveau. Built between 1904 and 1912, it stands out for its functional design and use of modern materials such as glass and steel. The facade, minimalist and adorned with geometric patterns, reflects Wagner’s intention to combine aesthetics and utility. The interior is equally innovative, with large open spaces designed to improve ventilation and the circulation of natural light. This building represents a synthesis of tradition and modernity, laying the groundwork for modern European architecture.