Staircase

So, here is a 3D model of a spiral staircase. The same as real spiral stairs this 3D staircase winds around a central pole. A pure spiral generally assumes a circular stairwell. The steps and handrail are equal and positioned screw-symmetrically. So, those are the features of any spiral staircase even if it is 3D model. And talking of this particular spiral staircase 3D model, one should mention that it is quite tight what makes this staircase 3D model very space efficient in the use of floor area.