The second of the Campus Martius tours continues west from the Pantheon, and includes the Piazza Navoa, the most famous and beloved of all Rome's great cityspaces (depicted above at manmade flood tide and in full August-festival array). It also includes, at S. Ivo della Sapienza and S. Maria della Pace, an introduction to the work of Bernini's two great contemporaries Francesco Borromini and Pietro da Cortona. The three architects are generally considered something of a triumvirate . . .