This is a must for every tourist coming to Milan for the first time. The Dome, inside and outside. Going inside is for free. But if you want to be closer to the sky, there's a fee: by lift, 12 euro/adult, by stairs, 7 euro/person. I took the stairs and I got on top in less than 5 minutes. It wasn't difficult at all. And the view and the lace of stone really worth the effort.