Up the sides of this doubly extinguished crater, and down the exterior flanks of the mountain, run steep, narrow, tortuous and gloomy, the flagstone-paved streets of the old city. So steep are they in some parts, that stairs have to take the place of the sloping flagstones, which are often laid at such an angle of declivity as to render wheel-traffic impossible. On the highest pinnacle of the rim, overlooking the hollow of the once crater, stands the Cathedral, on such uneven ground, that its east end is supported by a lofty baptistery, built underneath it on the rapid descent. In the most ornamented style of Italian-gothic architecture, and picturesque, though quaint, in its parti-coloured livery of horizontal black and white stripes in alternate courses of marble, the old church still contains a wonderful quantity of medieval Sienese art in many kinds. Carving in wood and in stone, painting in fresco and in oil, inlaid work and mosaic, richly coloured windows and gilded cornices, adorn walls, floor, and roof, in every part. The whole history of art from the early days, when Sienese artists first timidly essayed to imitate barbaric Byzantine models, to its perfect consummation in those glorious ages which immediately preceded the downfall of Italian liberty, is set forth in this fine old church, as in a rich and overflowing museum. Some half dozen popes sleep beneath sculptured tons of monumental marble in different parts of it,—among them two of the very old Sienese family of Picolomini. [Sidenote: FONTEBRANDA.] On another peak, or spur, of the deeply seamed mountain, stands the huge unornamented brick church and monastery of St. Dominic, so situated, that between it and the Cathedral is a steep gorge, the almost precipitous sides of which the old city has covered with stair-like streets. Deep at the bottom of this gorge, near a gate in the city wall, which runs indefatigably up and down the mountain ridges and ravines in its circuit around the spacious city, now a world too wide for its shrunken population, is that old fountain, which one passing word of the great poet has made for ever celebrated. Here is still that Fontebranda,[1] which, with all its wealth of sparkling water, the thirst-tormented coiner in the thirtieth canto of the Inferno, less longs for than he does to see in torment with him those who had tempted him to the deed he was expiating.