It's well known among pedants that spiral staircases aren't spirals at all, but helices. A spiral staircase, apart from not needing any stairs, would not take you through the "y" dimension, without which a staircase is pointless. You'd just go round in ever-decreasing circles, on a spiral staircase. In other words, and at the risk of labouring, straining or overstating the point, spiral staircases are badly named. And helical staircases, even when correctly designated, are a bit common.
That's why the new Moot House has a double-helix staircase.
You could say innovative architecture is in our DNA. Or possibly vice-versa.