N.B. The access to the Cathedral is always free, without ticket/booking.

Santa Maria del Fiore is one of the largest churches in the world. The plan consists of a triple-nave basilica with the presbytery area nested within, dominated by the large octagon of the immense dome, around which are three radial apses (or “tribunes”), each consisting of five chapels. The cathedral is 153 meters (502 feet) in length, 90 meters (295 feet) wide at the transept, and 90 meters high from floor to base of the dome lantern. The title “Santa Maria del Fiore” (Our Lady of the flower) alludes to the name of the city, "Florentia", or “city of flowers”, “destined to bloom”, and to its emblem, the Florentine lily.

The first stone of the new cathedral was laid on 8 September 1296, and the task of erecting it was entrusted to Arnolfo di Cambio. His project was similar in plan but smaller than the current building, which instead corresponds to the expansion developed by Francesco Talenti, beginning in the mid-14th century. The church was consecrated at completion of the dome, by Pope Eugenio IV, on 25 March 1436.

The external walls are covered in white, red and green marble with geometric figures and stylised flowers. The sides are adorned with four elegant mullioned windows, eight circular windows and four monumental portals richly adorned with sculptures.

The facade is a 19th-century neo-Gothic masterpiece, designed by De Fabris and adorned by the greatest Tuscan artists of the time. It replaced a previous decorated wall from the late 1600s, which followed on the demolition of the still earlier and unfinished medieval façade begun by Arnolfo di Cambio.