The artwork "sky Cross" by the Düsseldorf artist Thomas Schönauer consists of three superimposed floating crosses. There is a total of 15 meters long, 11 meters wide and 4.5 meters high. Surrounded it is at the bottom of a heart and a grassy area in the form of five petals. These are all symbols of the seal of Martin Luther, called the Luther Rose, which is modeled on the central 40 meter diameter space in the Luther Garden. The sculpture connect the grip with the skyward growing trees, the artist explains Schönauer. They intended to strengthen "one's own power and responsibility for the conscious participation of respectful coexistence and lebbareren future"
