The Aubad is a 50,000-square-metre (12-acre) man-made lake in Tulln on the Danube, Austria. It is the centerpiece of a recreational park (Erholungspark) that includes facilities for swimming, as well as a 10-hectare (25-acre) area for sport and leisure activities—such as soccer, volleyball, baseball and basketball—and 15 hectares (37 acres) of woodland.