Christo and Jeanne-Claude
Windhorst purchased part of the Christo and Jeanne-Claude collection, including documents and objects (such as scaffolding) involved in the 1995 Reichstag "wrapping". In November 2015, Norbert Lammert, President of the Bundestag, and the artist Christo opened an exhibition displaying 400 original drawings and sketches of the wrapping after Windhorst donated the works to the Bundestag until 2035.