The Baptistery of San Giovanni
The ceiling of this 9th Century octagonal chapel, which stands as you know on the piazza in front of the wedding-cake-looking 19th Century facade of Cattedrale di Santa Maria del Fiore (Firenze's Duomo), is Byzantine in style. Those medieval Byzantine artistic conventions had staying power and remained influential through the early and mid-Renaissance and, to my mind, they remain powerful. (In his later years, even Botticelli returned to them, as I learned last week, due at least in part to the influence of the evangelical friar Girolamo Savonarola.)