Affenkasten, Historical building in Aarau, Switzerland.

The Affenkasten is a listed building at Hintere Vorstadt 18/20 in Aarau, with a second entrance at Vordere Vorstadt 15. It was built in 1904 in the neo-Gothic style, and its three-part facade on Hintere Vorstadt has a steep ornamental gable in the middle section. Since the restaurant closed, the former dining rooms have housed a Thalia bookshop.

The building was constructed in 1904 for the Feldschlösschen brewery and replaced three older town houses that previously stood at this location. Its name references the Brewery zum Affenkasten from 1850, which gave the site its distinctive identity.

The building served as a gathering space for local associations and hosted various artistic events before its conversion to a bookstore. This role made it an important part of the city's cultural life for decades.

The building is located in the old town and easily accessible as it sits on a main street. Visitors can admire it from outside and explore the bookstore inside, which operates during standard retail hours.

The monkey figures sit above the two entrances, not on the roof, and recall the brewery zum Affenkasten founded in 1850 by Robert Pfisterer, which Feldschlösschen took over in 1895. The building itself went up in 1904 for Feldschlösschen, replacing three older town houses.