Affenfelsen, High-rise building at Gisselberger Straße, Marburg, Germany.

Affenfelsen is a 13-storey tower block on the southern edge of Marburg, a few metres from the Lahn and just outside the Südviertel. Hans-Werner Schreyer designed it in the Brutalist style, and it was built from 1971 to 1973. Its stepped, terraced form gave rise to the popular nickname.

The Affenfelsen was built from 1971 to 1973 to a Brutalist design by Hans-Werner Schreyer. It replaced the Wirtshaus an der Lahn, an inn documented since at least 1783 on the only road to Frankfurt, which was demolished in 1970. The inn had succeeded the Hof zur "Sorge", destroyed in the Thirty Years' War, and in the 19th century had such a poor reputation that the university feared it would lead students astray.

The nickname "Affenfelsen" (monkey rock) follows a German tradition of calling terraced concrete high-rises by that name. The site was long occupied by the Wirtshaus an der Lahn, a roadside inn on the only road to Frankfurt; in the 19th century the university worried it would lead students astray. It was demolished in 1970.

The building sits at a major traffic intersection with good connections to public transportation and nearby shops. Multiple vantage points throughout the structure offer views across Marburg, particularly from the upper floors.

The nickname "Affenfelsen" (monkey rock) follows a German tradition of calling terraced concrete towers by that name, as was already done for similar buildings elsewhere in the country. The 13-storey block was designed by Hans-Werner Schreyer and built from 1971 to 1973; residents value the view over the city, while critics call it a blight that does not fit the restored old town.