Escalier central du château de Chambord, Stairs in Chambord castle, France
The central staircase of Château de Chambord, a monumental architectural marvel.
Designed by Leonardo da Vinci in the 16th century.
Symbolizes French Renaissance architecture at its peak.
The two flights of stairs are set around a hollow core, giving an illusion of a double helix.
It's thought to have inspired the design of the Châtelet metro station in Paris.
Location: Chambord
Sources: Wikimedia, OpenStreetMap