When I was young, I was fascinated with this illusion. I would draw it in many variations. For Optical Tricks I decided to attempt it photographically. I began by reflecting paper towel tubes into a sheet of glass, aligning the reflections with square cardboard pillars behind the glass.

My experiment with glass and cardboard helped me determine the exact size of the model. A square arch and three round columns were made of wood and covered with a thin layer of spackling compound to create a stone-like surface.

Water-based paints were used to enhance the stone texture of the model, background surfaces, and rubble. A sheet of glass with a slightly reflective coating divides the set. Careful lighting hides some parts of the model and highlights others, resulting in the illusion of an impossible structure.

The final scene as it appears in the book. The edges of the glass and the round columns in this picture are clues to how the illusion works.