… we go, looking down over a staircase that was, for me, the highlight of the building in which it’s encased. Known as the Snail Staircase, the Spiral Staircase and as the Momo staircase, I think of it simply as Practical Art.

Giuseppe Momo’s two staircases, built during the Great Depression, dance together in what’s known as a double helix – a symbol that has subsequently, with scientists’ identification of the double helical DNA strand, come to symbolise life itself.