if you're particularly nimble or enjoy a challenge crossing vertical lines, then this staircase by HSH Architects might be right up your alley. Made from 10 mm thick sheet metal, this fascinating and somewhat menacing means of getting from A to B was designed for a home in Prague, and there's no word as to if it's actually in practical use or not.
From the designer's website we drew this text about its construction:
adjoining steps connected with an oblique external side joist form a
bracket anchored in the wall. Each of the brackets is constructed as a
rigid frame. The higher steps bear mainly drawing forces, while
pressure is transmitted through the lower steps."
Certainly beautiful to look at but also a potential threat and hazard to life and limb, is what I gather. No word on whether this will go into production, but I imagine it would only be for a select few sure-footed souls.
HSH via CubeMe