The authors present from a heuristic viewpoint an elementary study
of the unusual magic square (GMS) found in the outstanding Gaudí’s
Sagrada Famìlia Temple in Barcelona. Its magic sum is 33 and it features
on rows, columnns, diagonals and 2/2 broken diagonals, and on many 2×2
subsquares, such as the central one or the one formed by the entries at the
four corners. Elementary Group Theory is introduced as a natural tool in
the study of the magic square in order to analyse how these magic-sum
preserving structures wander on the torus (Z/4) × (Z/4), the geometric
counterpart of the plane square