See, this place is massive. In fact, if anyone would ask me, I would prefer considering the whole Piazza dei Miracoli as the main attraction of the city, not just the leaning tower. And yet everyone seemed to be obsessed with the architectural faux pas, posing for photographs where they seem to be holding the tower up, and so forth. I'll show you some photos of those, but not thi time. This time, I am only showing you interior photos of the Cathedral.
It is actually a massive cathedral, made with white marble but the interior is also very impressive. This is the only free thing you can see in the Piazza dei Miracoli: if you want to enter the Camposanto as well as the Baptistry, and of course the Leaning Tower, you have to pay an entrance ticket. This one, however, you can enter for free. You just have to get a ticket, because they scan the ticket every time someone enters this place.
We spent a couple of hours here, wandering along the marble corridors and staring at the massive paintings that adorn the walls. We aren't religious, but watching religious people do their thing is also an interesting thing to do.