In the image, you are looking at a monumental stone spiral staircase inside the Château de La Rochefoucauld, in the Charente department of southwestern France (today often listed as La Rochefoucauld-en-Angoumois).
Online, this staircase is frequently credited to Leonardo da Vinci. We can say with confidence that it is a Renaissance “grand staircase” built around 1520 during major works ordered by Anne de Polignac, lady of La Rochefoucauld. The château’s own architectural notes describe a spiral stair set inside a square of about 6.75 meters, with a distinctive twisted central core (the “newel”), and 108 steps climbing to the upper galleries. Above, the vaulting closes like a stone palm tree, a ribbed ceiling effect that was a showpiece of high-end masonry.
The Leonardo link sits in the “attributed to” category.
The château presents the design as connected to drawings attributed to Leonardo that were supposedly provided by the king. That is a real tradition around the building, but it is different from having a surviving signed plan or a documented contract.
This second photo was taken at Château de Chambord in the Loire Valley, famous for its double-helix staircase. Stories about genius staircases travel easily, because stairways are where architecture becomes bodily: breath, rhythm, and the small decision to take just one more step.
P.S: The ones at Chambord are double helix staircases.
The winding staircase at Loretta Chapel is also a masterpiece