House of Stairs. November 1951 Lithograph "House of Stairs" has an unusual perspective. If the grid lines for this drawing were visible, one would see a network of curved vertical lines that met in the centre at three points along a vertical axis. The vanishing points have various functions for the Curl-Ups in the stairwell. The curved lines of the drawing allowed Escher to make opposite dimensions (above, below) flow into each other.