A classic 1955 lithograph by M.C. Escher, exploring spatial ambiguity and impossible architecture through a dual-perspective scene.

Convex and Concave is a lithograph by M.C. Escher, created in 1955. The work explores the ambiguity of spatial perception through a complex architectural scene. Escher employs a dual perspective, where the viewer is invited to interpret the same structural elements as either convex or concave depending on the focus point. The composition features a series of vaulted rooms, staircases, and balconies populated by various figures, including a woman carrying a basket and a man playing a trumpet. The architectural logic shifts as the eye moves across the print. What appears as a ceiling in one section of the building transforms into a floor in another. This reversal is achieved through the precise manipulation of light and shadow, which defines the volume of the arches and columns. Escher uses a monochromatic palette to maintain clarity, allowing the viewer to focus on the geometric contradictions rather than colour. This print is a characteristic example of Escher's interest in tessellation and non-Euclidean geometry. By integrating human figures into an impossible space, he creates a narrative that feels both domestic and alien. The inclusion of small details, such as the lizards on the lower level and the hanging banners, provides a sense of scale that contrasts with the disorienting nature of the architecture. The work remains a study in how the human brain attempts to resolve conflicting visual information into a coherent three-dimensional structure.