This is one of the most recognizable pieces of art in the world and something you must experience in Milan. However, you will need to plan ahead as only a maximum of 35 people are allowed to see the painting at one time in 15 minute slots.
Reservations are an absolute must. We tried getting tickets through the official website 2-3 months in advance, but still could not get anything and had to go with a guided tour through GetYourGuide (suspect the guided tours take up a lot of the slots as both our time slot and the one after were led by guides. Through GetYourGuide, we were given detailed instructions on where to meet. We found our guide, Anna Pinto, holding a GetYourGuide sign at the promised time where she gathered our group of around 30 people and briefed us on logistics, the history of Milan, the church, Leonardo da Vinci and the Last Supper. We each got radio receivers so we could hear her clearly.
We were then led to get our tickets which required us to show an ID (driver’s license was fine). The name had to match the name supplied on your reservation. There were lockers in the ticket office in case you had large bags or any food/drinks that were not allowed inside. From there we were led into the entrance where there was a quick security check and then off to a holding area outside the refectory. During this time our guide continued sharing details about the refectory and the painting. This point is an excellent time to get your cameras ready. Once the automatic glass doors open, you will walk inside and to your right is the Last Supper.
Our guide continued with thorough explanations, though I honestly was not paying attention as I was trying to take photos. The painting is lit dimly but enough that you can see clearly and take photos (no flash allowed of course). The rest of the room though is even dimmer making it challenging to take photos with people. Our entire group was unsurprisingly clustered in front of the Last Supper. There is another painting opposite the Last Supper depicting the Crucifixion that no one was paying much attention to.
When your 15 minutes is up, you will be shepherded out into a separate room that has more details about the Last Supper. Our guide continued with some very insightful details into the history of the painting. Finally we ended up in a courtyard and parted ways with our guide. By the courtyard, there was a souvenir shop and toilets. The whole experience lasted about an hour. After exiting, you can visit the church next door for free.
Overall, the experience was a bit hectic with the time limit, but certainly one of the things you must do when visiting Milan. While having a guide added to the cost (4 times more than a regular ticket), it greatly helped with the insightful information and details an unguided tour would not have had. Our guide in particular spent the entire time feeding us information and spoke clearly in English.