“Sky and Water I,” created by the renowned artist M.C. Escher in 1938, is an illustrious example of the Op Art movement and a significant piece in the genre of tessellation. The artwork illustrates a seamless transition between sky and water, with the upper portion depicting birds transforming into fish as one moves downward through the composition. Utilizing a monochromatic palette, Escher masterfully intertwines the forms of birds and fish, creating an optical illusion that challenges the viewer’s perception of positive and negative space. This intricate interplay encapsulates the essence of tessellation, as each element fits perfectly into the next, demonstrating Escher’s profound understanding of geometry and his innovative artistic vision.