Staircases are one of the oldest components of architecture; throughout history, they have not only been the focal point of grand designs, but played a starring role in ceremonies, fairy tales, legends and landmarks. Cinderella lost her slipper on one; Harry Potter slept under one; Led Zeppelin sang about one. Staircases continue to inspire the modern world. From sweeping spirals to wrought iron art, we explore the best modern designs.