Operation Market Garden (September 17–25, 1944) was an Allied military operation, fought in the Netherlands and Germany in World War II. It was the largest airborne operation of all time. The operation plan's strategic context required the seizure of bridges across the Maas (Meuse River) and two arms of the Rhine (the Waal and the Lower Rhine) as well as several smaller canals and tributaries. Crossing the Lower Rhine would allow the Allies to outflank the Siegfried Line and encircle the Ruhr, Germany's industrial heartland. It made large-scale use of airborne forces whose tactical objectives were to secure a series of bridges over the main rivers of the German-occupied Netherlands and allow a rapid advance by armoured units into Northern Germany.