Ingolstadt, a city of 125,000, is located on the Danube River in the Free State of Bavaria and is itself a "free", independent administrative district. Ingolstadt is the second largest city in southern Bavaria, only Munich is larger, and it is also Germany's newest urban centre - Ingolstadt's population reached the 100,000 mark as recently as 1989. The urban area extends both north and south of the Danube. In the old town, still intact to a great extent, are structures from all of the cityâ€™s historical eras. Among the oldest buildings are the duke's castle and St. Moritz Church, both from the 13th century. The city's landmark is the Kreuztor from the 14th century; both this gate and large sections of the city wall are still intact. In addition to many such representative structures, the numerous townhouses with magnificent baroque façades are also worth a visit. From both the Scherbelberg, a hill built from debris left by the Napoleonic Wars, and from the Pfeifturm, a 14th century watchtower, visitors have a great view of the old town. Moreover, Ingolstadt is known for its many green spaces and parks. The "Glacis", a series of green spaces surrounding the actual centre of town, was previously the area in front of the former fortress wall. Today, Ingolstadt enjoys international fame as the home to the Audi headquarters and production facilities.