A paradoxical pavilion from Optical Tricks
Strange as it may seem, both structures here are one and the same. But in the picture below, the alignment of the foreground with the background results in the illusion of a two-story pavilion. When seen from the side the optical trick is revealed.
The balcony is attached to the arches in the foreground, but the top of the foreground archway is cut at an angle that matches the angle of the walkway’s bottom edge when seen from a particular vantage point. For another clue, note the shadow of the tower in the picture on the right.
Going Up?, ©1998 Walter Wick,
from Walter Wick's Optical Tricks