In Italy, there are countless precious artworks in all forms. They can be fragile or vulnerable to human breathe. The Last Supper by Da Vinci is an example. The fact that the Italians choose to share and open for visitation so that visitors like you and I should not be taken for granted. A lot of them may be undergoing renovation and restoration so they may be closed. They may also occasionally open new things to public that may surprise you in different ways. For this reason, personally I treat encounters with these objects or artworks as once in a lifetime opportunity. They are precious, but you don't know if you will be able to see them again and again due to various reasons.
When you have an opportunity to see precious artwork like this, sometimes requires more work, but it's worth it.
More work means either making reservations in advance or long wait time or fees or physical energy.
Because Italy has so many attractions that fall into "popular" category, planning ahead definitely helps, but also be aware of additional effort required to.
This one falls into this description.
More work in this case: Making advance reservations isn't easy for visitors less than 10 people, literally impossible. They also are not responsive to email inquiries. Their online reservation system is difficult. The online information can be confusing too. I made so many inquires including filling out its webform and still got me nowhere. That's the very reason I am giving it a 4 instead of a 5 out of 5.
Thankfully, there is a workaround. You must go there in person, ask them at the ticket counter. They will share with you their upcoming guided tour in Italian and English for the day. If they have space available, you can make reservations and obtain tickets on spot. More administrative work. If they don't have availability, they may be able to help you find tickets for future dates. Please work with the ticket office staff to sort it out. The entire team there are nice and helpful. Most speak good English.
To see this place, you must join a guided tour offered by them. There is no other ways to do it. The maximum group size is capped at 10-15 or so.
They do charge a fee.
Once you have gotten your ticket, then it's a smooth sailing towards the end.
They would give you an overview in a presentation room.
The frescos are in two levels. They thoughtfully built a scaffold so you could see these artworks at eye level, up close. The actual artwork is located on the 2nd and 3rd level. They give you 15 minutes on each level. Once 15 minutes is up, please respect their instruction and leave the current level to the other one. Once you are done seeing both levels, you are directed back to the ticket office area. That's the end of the tour.
There is no elevator, you must be able to climb stairs from the ground level up to three story high, if you can't, please do not sign up.
I personally suggest and recommend that you wear a mask to reduce human breath damaging artwork. But this is not mandatory when I was there.
This place is worth visiting. Highly recommend.
Good luck with making advanced reservations and getting tickets.