San Carlo alle Quattro Fontane
The interior of San Carlino picks up and intensifies the alternating convex and concave wall treatment, with such a profusion of columns and niches that it is hard to discern the complicated geometric floor plan. Nor do you get any help in grasping the true shape of the church from looking up at the dome, which is oval-shaped and does not seem to be an extension of the highly confined area for the human being below - but rather a soaring intrusion into Heaven above, bathed in light from semi-hidden windows. Symbols are central to Borromini's approach to building. Many of the shapes were taken from ancient Roman buildings and pther architectural models, but their use by Borromini was revolutionary for he was trying to design buildings which were not so much walls and floors and ceilings as undefinable magical dimensions which force the beholder into spiritual contemplation. In the cloister, for instance, there are no corner columns holding up the heavy colonnade above, and the alternating shapes of the bays prevent the eye from coming to rest.