La spirale cilindrica nelle scale rinascimentali e barocche
The helicoid staircases are often used in the architecture since the ancient age. In the medieval period this type of stair is used into towers, fortifications or bell towers with a main functional value. Starting from renaissance the architects thought to give them also an high architectural value.
The first was Bramante in Vatican (1507), then Vignola in Caprarola (1559), Mascarino in the Quirinale palace (1585) and Borromini in the Barberni Palace (1633).