The square has three identification spaces - three topological shapes that can be produced by gluing opposite sides to each other.
This triptych features all three - the Torus, the Klein Bottle and the Projective Plane - in a selection of interesting immersions into 3 dimensions.
The Roman surface or Steiner surface was discovered by Jakob Steiner when in Rome. In addition to being an immersion of the projective plane into 3 dimensions, it is also a projection of the Veronese surface - one of the early examples one meets in studying algebraic geometry.
The steel version of this was
exhibited at the Joint Mathematics Meetings 2019.