History

In 1516, Leonardo da Vinci designed a double helix staircase for the Château de Chambord in the Loire Valley, France.

This staircase is unique because it consists of two intertwined spiral staircases that allow people to ascend and descend without obstructing each other. pic.twitter.com/TCCMvEYPg7

— Massimo (@Rainmaker1973) December 3, 2023