Baptistery of St John

Dedicated to Florence's patron saint, John the Baptist, this octagonal building is widely considered the oldest surviving monument in the city, with construction likely already underway by the mid-11th century and continuing on into the 1100s — centuries before the neighbouring cathedral existed in its current form. For hundreds of years, every Florentine born in the city, including Dante Alighieri, was brought here to be baptised, and the building held that civic role for the whole population well into the modern era.

Its green-and-white marble cladding, echoed later on the cathedral and Santa Maria Novella, established a distinctive local style that Florentine architects returned to again and again. Medieval Florentines were so taken with the building's antiquity that they long believed — mistakenly — that it had originally been a Roman temple to Mars, a legend that only added to its prestige as the spiritual heart of the city.

The Baptistery's fame today rests chiefly on three sets of bronze doors made for its three entrances. Andrea Pisano cast the south doors in 1330, the earliest and technically the hardest, since bronze doors of that scale had not been made in Italy for centuries; Lorenzo Ghiberti won a famous competition in 1401 to design the north doors, completing them by 1424, and was then asked back to create the east doors, finished in 1452 after 27 years of work.

Those east doors so impressed Michelangelo that, according to Giorgio Vasari, he declared them fit to be the "Gates of Paradise" — the name has stuck ever since. Their ten gilded panels narrate the Old Testament from the Creation to Solomon and the Queen of Sheba with a depth of perspective almost like sculpted paintings; the originals, badly damaged in the 1966 flood, now live safely in the Museo dell'Opera del Duomo, while faithful bronze copies stand in their place on the building itself.

Entry to the Baptistery is included in the combined Duomo complex tickets (such as the Brunelleschi Pass or Giotto Pass), which also cover the bell tower, the cathedral museum and the crypt of Santa Reparata, and are valid across multiple sights for 72 hours from first use — there's no separate standalone ticket. Because time slots for the cathedral's dome climb are limited and sell out weeks ahead in high season, it's worth booking the whole complex online before travelling rather than turning up and hoping.

A logical way to visit is to pair the Baptistery with the dome climb and Giotto's bell tower on the same day, since all three face onto the same small square and the walk between them takes minutes. Inside, look straight up: the 13th-century gilded mosaic ceiling covering the dome, showing a monumental Last Judgment among other biblical scenes, is easy to miss if you're focused on the doors on your way in.