City fortification, Medieval city gate and fortified tower in Baden, Switzerland.

The city fortification is a medieval gate and tower structure located at the intersection of Weite Gasse and Schlossbergplatz in Baden. The building features stone defensive walls surrounding a multi-story central tower with thick masonry construction.

A first tower stood at the north edge of the old town around 1360 and was demolished some 80 years later. From 1441 to 1448, during the Old Zurich War, the local master builder Rudolf Murer worked on a new gate tower with a zwinger; the unfinished tower withstood a Zurich attack with a battering ram on 8 November 1445. In 1481–1483 Martin Grülich of Brugg raised it by two storeys, adding four oriels, two tower clocks and a roof turret. It was placed under monument protection in 1925.

The fortification demonstrates how medieval inhabitants protected their town through strategic construction. The design reflects everyday military thinking of that time, with its arrangement showing how people defended their city gates.

The structure sits in the old town and is easy to reach on foot since it occupies a visible corner location. The site offers good views of the surrounding historic architecture and nearby streets.

The structure uses local stone from the Aargau region, which gives it its distinct character. This material choice reveals how medieval builders worked with the natural resources available in their surroundings.