The Royal Maas Yacht Club (Dutch: Koninklijke Roei- en Zeilvereniging De Maas) is a Dutch yacht club and rowing club located in the centre of Rotterdam. Members are able to engage in sailing and rowing and the yacht club's name, de Maas, stems from the name of the river Nieuwe Maas flowing through Rotterdam. The clubhouse designed by the architects Barend Hooijkaas jr. en Michiel Brinkman, was opened in April 1909. This elegant Jugendstil creation, which just survived the bombardment of the centre of Rotterdam in May 1940, is an important example of modern architectural art in the Netherlands.