You don’t expect to see a spiral staircase made out of concrete. Wrought iron, yes. Steel, sure. Wood, certainly. But cement? What a bold idea. And this just isn’t any old spiral staircase. It’s the patented Helicoidal Staircase, from Rizzi. Made of monolithic elements – it has no central support column. This leaves unprecedented space in the stairwell, not just for the comfort of the climber, but for toting large pieces of furniture to the next floor up. The organic curves just flow up the stairs. The structure is made from cement, yet it seems to be floating on air. Now, that’s a design.