A manhole cover that has symmetry of type 22* in Slovenia.
In Lugano, a manhole cover with a scheme of symmetry of type *632.
A manhole cover in Paris with cyclic symmetry, of type C12.You can see an other one.
A manhole cover that has symmetry of type 4*2. You can see also a detail.
On the floor of the Gallery, in Milan, a rosette with a dihedral symmetry group, a D16 gro...
A manhole cover with dihedral symmetry of type D16 (if we ignore the writings on the exter...
drains and manhole covers