The religious centre of Firenze consists of three buildings; The Cattedrale di Santa Maria del Fiore (the Duomo itself, featured in image 015618), the octagonal Baptistery (on the left of the frame) which is one of the oldest buildings in the city having been constructed between about 1059 and 1128, and Giotto's Campanile, which was previously seen in image 015614.

As I said in that image, the Campanile may have appeared to be attached to the Duomo but you can see more clearly here that it is a freestanding building. The area around the Duomo is probably one of the more trafficked areas in the city, at least for tourists.