Düsseldorf's Altstadt (Old Town) is also home to some of the city's most beautiful churches. For instance, the Sankt Lambertus Basilika, which was first built in the 13th century, and which with its twisting spire helps make Düsseldorf's skyline unique. In conjunction with the Schlossturm (Castle Tower) and the River Düssel, the basilica remains part of the Old Town's original core. This church's parish altar also houses a shrine containing relics of Saint Apollinaris, the city's patron saint.

Burgplatz is where the little River Düssel, which gave the town its name, flows into the Rhine. In the background is the former collegiate church, St. Lambertus, with the shrine of St. Apolinaris. Next to the bridge over the Düssel, the monument to Düsseldorf being granted the privileges of a town demonstrates impressively more than 725 years of town history (town status granted in 1288). The square is dominated by Alter Schlossturm, the old palace tower (now the Schifffahrt-Museum navigation museum) and last testimony to the princely palace from the 13th century that fell victim to flames in 1872. The generously proportioned Rhine embankment promenade is considered one of the most beautiful on the Rhine. Upriver, the Medien Hafen is characterised by outstanding architectural creations, and the elegant district of Oberkassel on the opposite bank by art-nouveau facades.

Featuring elaborate Moroccan and European architectural styles, Église du Sacré-Cœur de Casablanca is one of the landmark buildings in Casablanca. Once a Roman Catholic church, the glistening-white Art Deco cathedral has functioned both as a school and as a theatre.