The line for the Florence Duomo.

I can't tell you if the line will be longer than when it was for us when we were there (mid-day, June) but it was wrapped a good 50-60 yards around the side - to the begining of where the chapels are on the sides, where the duomo "T"s. This length only took 15 minutes and moved very quickly. I would definitely say it's worth checking out, but I believe going to the top of the dome is closed on Sundays.

Our experience in late May was the same as Ken's. A long line around and to the back of the Duomo. It took about 30 minutes to get in. Once in, we were a bit disappointed with the inside. It's dark and mostly empty except for the area where the services occur. You won't be able to go under the dome unliess you attend the services as the dome is directly over the pews and other areas involved in the mass. We were out of there in 30 minutes. If you have time to see the real treasures of il Duomo, they are across the street (left rear of church) in a great museum. It's called The Opera del Duomo Museum and we were in there for a couple of hours. Brunelleschi's orginal design models for il Duomo are in there.

I was in Florence in mid June 2004. We were with a tour group so we actually did not wait to enter the Duomo. But I went back later in the day by myself to climb the dome and the line was long, but only took 15 minutes or so to make it through the doors. It was completely worth the wait and the climb! I did NOT have to attend the services to see the dome like Larry said. The services were actually going on when I made the climb, but the entrance to the dome is from the outside and the only time you are actually inside the sanctuary is when you are on a walkway at the base of the dome which is too far above the congregation to be a distraction. If you can fit it in your schedule I would DEFINITELY recommend climbing the dome! It is unique because of its "double dome" design and you get an amazing view of the city.

How about winging it and if the line is too long take a climb up Giotto's tower. I've never seen much of a line there and you get a similar city view. (And a cool view of the dome) The dome is amazing but if time is short, it may be a decent option. (I also 2nd the idea of catching the Duomo museum)

No offense to anyone who loves the Duomo, but, I actually hated it. The place was so blahzah and hardly and frescoes or mosiacs. I would never go to Florence again, even if I was paid. Sorry just my opinion.