The Cathedral of Santa Maria del Fiore, AKA The Duomo, which was completed in 1434, is the fourth largest church in the world. It is astonishing with a lively square built out front. If you have time, go inside and climb to the top for a bird's eye view of Florence.

To save yourself from what can often be an appalling queue, we would highly recommend booking skip-the-line tickets online in advance.