Portal des Klosters in Petershausen bei Konstanz 

This detailed pencil drawing by Karl Ballenberger depicts the portal of the Petershausen Monastery near Konstanz, Germany. The artist, known for his architectural drawings, meticulously captures the Gothic structure's intricate details, including the pointed arch, clustered columns, and a relief sculpture above the entrance depicting a central figure flanked by angels. This drawing, held in the Städel Museum, offers a glimpse into the architectural style of the monastery and provides an accurate representation of its historical significance.