It is located on the Danube, immediately north of the Austrian capital Vienna, from which it is separated by the Kahlenberg and Leopoldsberg hills of the Vienna Woods range. It has been separated from its twin city of Korneuburg on the left bank of the Danube since the river changed its course during the Late Middle Ages. Both towns are connected by a reaction ferry link. The municipal area comprises the northern tip of the Donauinsel as well as the high Mt. Exelberg and its telecommunication tower.