Abstract: A puzzle includes a set of non-border pieces and a set of border pieces. Each border piece includes at least one segment not adjacent to another piece when the puzzle is assembled. Each non-border piece includes a first arc segment having a convex shape and a second arc segment having a convex shape. The second arc segment is superimposed on the first arc segment, has a radius of curvature smaller than a radius of curvature of the first arc segment to which it is superimposed, and is shaped to interfit with a concave arc segment of an adjacent piece. Non-border pieces are shaped to each include a second arc segment that is concentric with the first arc segment of an adjacent non-border piece. Non-border pieces are shaped to each include a first arc segment that is concentric with the first arc segment of an adjacent non-border piece.