The Szilassi polyhedron is a heptahedron that is topologically equivalent to a torus and for which every pair of faces has a polygon edge in common. The Szilassi polyhedron has 14 polyhedron vertices, seven faces, and 21 polyhedron edges, discovered by L. Szilassi in 1977. Like the tetrahedron, each face of the Szilassi polyhedron touches all other faces.