Of course, the Cathedral, started in 1296, is the big draw, with Brunelleschi’s astonishing dome. The Cathedral and its campanile was finished by about 1418, but the striking neo-Gothic facade wasn’t applied until the 19th century. The dome, begun in 1420 and not completed until 1436, was remarkable for the time (especially considering it was designed and built by a goldsmith). The only dome nearly its size ever built was the Pantheon’s, but it had been constructed of concrete poured over a form, and there wasn’t enough timber in Tuscany to do that with the Florence cathedral, not to mention that it was to be higher than the Pantheon and was built over 170 feet above the Cathedral floor. It’s quite remarkable.