There is something mysterious and intriguing about spiral staircases. Atlas Obscura looks at some of the most magnificent spiral staircases in the world, with lovely pictures and facts you might not know. For example, the staircase at the Vatican Museum, pictured here, is actually a double helix, with one staircase going up and the other coming down. Link -via Curious Expeditions
How does that work?
Dont both of them go up and down?