Three dimensional relief puzzle

A three-dimensional relief puzzle comprising a plurality of puzzle pieces which are required to be initially assembled and fastened into a plurality of rows and subsequently assembled and fastened by rows into a composite having a rectilinear periphery, said puzzle pieces having substantially identical cross sectional areas and having varying heights substantially greater than the widths thereof, said puzzle pieces having planar side faces which are adapted to mate with each other in a predetermined manner to collectively form said composite, interlock means of varying sizes randomly disposed at predetermined varying heights in said side faces of said pieces except said faces which form peripheral surfaces of said composite, for securing said puzzle pieces to each other in said predetermined manner, said interlock means comprising projection means of varying size extending from the side faces of predetermined pieces of said puzzle and corresponding openings for close mating engagement with said projection means when said pieces are assembled into said rows and subsequently into said composite, said interlock means being thus disposed at a plurality of different heights throughout said composite, said puzzle pieces when assembled into said composite forming a planar lower surface and a curved upper surface describing a physical embodiment of a regular three-dimensional mathematical function.