Cathedral of Santa Maria del Fiore, Florence

This is a must see if you visit Florence. The dome itself is an architectural marvel AND an artistic masterpiece (inside). The top of the dome offers one of the best views of Florence besides the Piazzala Michelangelo from an astounding 92 meters. If you go, make sure you get the all inclusive ticket (for the bell tower, museum, cathedral, dome, and baptistery) it's WELL worth it. Another tip: BOOK a time in advance. The lines for people without bookings/reservations can take 1-2hrs easily. The other attractions won't require a booking. They never have a line except maybe the weekends.

Firenze is one of the most beautiful cities. Filippo Brunelleschi has created a masterpiece that endures for centuries. It's a beautiful church and worth waiting in line to see. You really need to climb the tower at the time of sunset for an incredible view.

Impressive cathedral!! The way the dome was built by Brunelleschi set the scene for the Renaissance architecture. Very much recommended its visit.

The inside and outside of the church are stunning. The Cathedral of Santa Maria is definitely a must-see when visiting Florence! The church itself doesn't require an entrance ticket, but you'll need one if you'd like to see the small museum underground. It shows some of the excavation work done underneath the church where a smaller, order structure (~5th century) once existed beforehand. It's actually quite interesting, and I definitely recommend visiting it as well.

Be aware you can get into the Cathedral itself for free (appropriately dressed) but may have to queue. Entrance to the bell tower, dome and museum is EUR 15 but you have to be fit and OK with heights to cope with the climbs - you won't see much of the inside of the Cathedral at ground level with the dome ticket as you're led straight to the stairs up to the dome. If you do go for the ticketed parts, get them from the ticket office on the north side of the Piazza opposite the Battistero and book 'skip the line' slots if you can. You will still have to queue in the 'skip the line' queue, it just won't be as long as the normal queue. Just make sure you're in the right one, it's not very clear and there are always people being turned away.