Oval staircase, Francesco Borromini, Palazzo Barberini, Rome, 1634. It serves the south wing of the palace, and complements a bigger one by Bernini on a principle both aesthetic and functional. The staircase is helicoidal and has a flattened oval plan, thus providing easier ascent… [1280×510] [OC]

…than circular staircases. Each turn comprises 12 Doric double columns with capitals decorated with small bees (the Barberini family’s heraldic symbol). Light comes through the oculus above as well as the windows in the façade. The staircase was accessed from the external portico and was intended for a more private use than Bernini’s..

Spiral-shaped structures, with all the problems involved in their design, were particularly congenial to Borromini’s eccentric spirit: he devised them in several drawings and in the architectural details of other works.

Bernini and Borromini were lifelong rivals. On a personal note, between the two staircases at the Palazzo Barberini, I prefer Borromini’s hands down. Bernini’s is a beauty too, don’t get me wrong ☺️