Stewart toroid

A Stewart toroid is a polygon with a hole through it that meets some or all of the criteria specified by Bonnie Madison Stewart in his 1980 book Adventures Among the Toroids. These criteria are as follows: all faces must be regular; faces that meet mustn't lie in the same plane; the polygon must be quasi-convex; the hole through the polygon must change its genus; and, the faces aren't allowed to intersect with themselves or each other. Stewart toroids, pierced relatives of the familiar Platonic solid, combine dazzling complexity with attractive symmetry.