Art Nouveau, Jugendstil in German, is an international style of art, architecture, and applied art, especially the decorative arts. It was often inspired by natural forms such as the sinuous curves of plants and flowers. Other characteristics of Art Nouveau were a sense of dynamism and movement, often given by asymmetry or whiplash lines, and the use of modern materials, particularly iron, glass, ceramics and later concrete, to create unusual forms and larger open spaces. It was popular between 1890 and 1910 during the Belle Époque period, and was a reaction against the academicism, eclecticism and historicism of 19th-century architecture and decorative art.