"The small oval church of San Carlo alle Quattro Fontane, lovingly called 'San Carlino' by the Romans, is a masterpiece of Francesco Borromini," says the guidebook, "and it was his first important commission in Rome, often considered his most innovative work. It is difficult to describe the structural richness of the façade; still more difficult to appreciate it, as the church stands right on the street in a cramped corner site, with traffic roaring mercilessly past it."
I made my first visit to San Carlino late at night when I couldn't go inside but when the street was relatively empty – just to see the shapes against the dark.
Later I went back in daylight several times. In all of Rome I believe this became my favorite building.
All walls and details were entirely white. What looked like stripes of contrasting paint was merely the effect of shadow. Borromini knew that the dome and a few high windows would be the only light sources and deepened the ledges to create the shadows for emphasis. One of the greatest things about San Carlino from the visitor's point of view was that no artificial lighting had been imposed on the structure and it could be seen as the architect intended. (My daughter wrote here yesterday about the dangers of attributing authorial intention, and those dangers are genuine – but authors are seldom in danger of having their texts distorted, messed with, chopped up or obliterated, as happens routinely to the works of architects – so to me the process of attributing architectural intention is quite different and is both inevitable and valid.)
