From the northern tip of the Zürichsee, the Limmat River starts its brief journey to the Aare and, ultimately, to the Rhine—and it neatly bisects Zürich at the starting gate. The city is crisscrossed by lovely, low bridges. On the left bank are the Altstadt, the grander, genteel pedestrian zone of the old medieval center; the Zürich Hauptbahnhof, the main train station; and Bahnhofplatz, a major urban crossroads and the beginning of the world-famous luxury shopping street Bahnhofstrasse. The right bank constitutes the livelier old section, divided into the Oberdorf (Upper Village) toward Bellevue, and the Niederdorf (Lower Village), from Marktgasse to Central and along Niederdorfstrasse, which buzzes on weekends. Most streets between Central and Bellevue are pedestrian-only zones, as is the Limmatquai from the Rudolf-Brun-Brücke to the Münsterbrücke.
Similar to the arrondissement system in Paris, Zürich is officially divided into a dozen numbered Kreises (districts), which spiral out clockwise from the center of the city. Kreis 1, covering the historic core, includes the Altstadt, Oberdorf, and Niederdorf. Zürich West is part of Kreis 5. Most areas in the city are commonly known by their Kreis, and a Kreis number is generally the most helpful in giving directions.