Illuminated hand coloured optical view of a large square in Vienna (Wenen). Beautifully coloured. The outlines and light sources of the buildings and windows are perforated (dots and figures). At the back of the print we see that the holes are covered with see-through paper. Some of the holes are coated with green, red and yellow paint. This gives the illusion of coloured lights when the print is held in front of a light source. Very neatly illuminated