Since it was rebuilt, Schloss Moyland has housed within its walls the former private collection of the van der Grinten brothers. It opened as a museum of modern art on 24th May 1997. The historic castle, its outbuildings and extensive gardens link 19th century architecture and landscape gardening with modern and contemporary artistic approaches, in a unique manner. The permanent exhibition in the rooms of the castle presents a selection of works from the van der Grinten collection. The outbuildings are used for presenting a regular series of temporary exhibitions which, together with a great many artistic events, have given the museum its reputation as a cultural centre of international importance.
Towards the end of the 17th century the original moated castle was altered and extended in the baroque style. In 1740, when it was owned by the Prussian monarchy, Friedrich the Great and Voltaire met here for the first time. In 1766 it was taken over by the von Steengracht family, who were also responsible for further changes in 1854. No less an architect than Ernst Friedrich Zwirner, the designer of Cologne Cathedral, was responsible for the new neo-gothic appearance. Until 1945 the castle was the permanent residence of the von Steengracht family, and a popular venue for day-trippers from the Lower Rhine area. After decades of gradual dilapidation, work began on restoring the building in 1987. Finally, ten years later, the museum was opened.
The former private collection of the van der Grinten brothers (Franz Joseph und Hans †) now forms the museum's permanent collection, which covers five floors in the main body of the castle. Thanks to their expert knowledge and continuous purchases over the space of 50 years, the two art enthusiasts built up a unique collection of exhibits from the 19th and 20th century. Almost all areas of fine art and applied art are represented here. Alongside examples from the various schools of modern art, the collection concentrates especially on the works of individual artists. The unique character of the museum derives from the personal contact between the two collectors and artists like Joseph Beuys, Erwin Heerich, Hermann Teuber and Rudolf Schoofs. At the same time, the museum contains the world's largest collection of works by Joseph Beuys.