Florence’s Cathedral, or Santa Maria del Fiore, is the world’s third largest church, after St. Peter’s in Rome and St. Paul’s in London. It is 153 meters long, 90 meters high, and 90 meters wide.  Designed by Arnolfo di Cambio, it was dedicated to Santa Maria del Fiore, the flower (‘fiore’) in question being a reference to the lily, symbol of the city. 

Santa Maria del Fiore was built over a previous cathedral, the second built in Florence, which had been dedicated to Santa Reparata. In fact, you can see the remains of that ancient church in the so-called crypt, which were brought to light in the 20th century and represent the most important evidence of the early stages of Christianity in Florence.