The document discusses the Art Nouveau movement, highlighting its decorative style characterized by intricate patterns and organic forms, with significant figures such as Alphonse Mucha and Antoni Gaudí. It details notable structures like the Hôtel Tassel, designed by Victor Horta, known as the first true Art Nouveau building, and Casa Batlló, a remarkable work by Gaudí. Additionally, it mentions the Karl Ernst Osthaus Museum, which houses a collection of art and serves as a center for Art Nouveau and expressionist art.