Scala Elicoidale, Giuseppe Momo, 1932. It is also known as the modern Bramante Staircase, as it was inspired by the staircase (actually a ramp) built in 1505 by Renaissance master Donato Bramante. Momo’s version, however, features a double-helix design, two intertwined spirals…[1280×1280][OC]

…with each spiral serving a distinct purpose: one for ascending and one for descending. This innovative design elegantly solves a fundamental problem of visitor management—allowing uninterrupted, two-way traffic without people crossing paths.

The original 1505 Bramante staircase was famously designed to allow Pope Julius II to ascend to his private residence without leaving his carriage, as walking up multiple flights in heavy papal vestments would have been impractical.​

The modern staircase encircles the outer wall of a stairwell approximately 15 meters wide, in the shape of an inverted cone, with a clear open space at the center. The balustrade is characterized by ornately worked metalwork that, as contemporary observers note, appears to lighten the visual weight of the double helix structure. Above the staircase is a skylight or canopy that provides natural illumination to the stairs.​

Momo’s staircase is decorated with the heraldic arms of Pope Pius XI (r. 1922–1939), marking its period and papal patronage. Notably, since the new entrance to the Vatican Museums opened in 2000, the staircase has been primarily used as an exit route only—visitors now descend the Momo staircase rather than ascending it.​

There is considerable speculation among architecture historians and professors that Momo’s 1932 staircase—particularly its skylight, atrium design, helical ramp structure, and innovative technical construction—influenced Frank Lloyd Wright’s design for the Solomon R. Guggenheim Museum in New York. While not definitively proven, the similarities in spiral geometry, lighting strategy, and the interplay between the central void and the surrounding ramp suggest a possible architectural lineage.​

My apologies for inaccuracies and mistakes.