What is this I read about booking in advance to see the Last Supper at Sante Maria Delle Grazie?

Reservations are recommended, since only 20 people are allowed to visit it at one time, and then for only 15 minutes. You can make reservations (between 8 a.m. & 8 p.m. Monday thru Saturday, Milan time) directly at (39) 02-89421146 up to 60 days in advance. Cost is 12,000 lire.

Try SelectItaly to make reservations

Many thanks to those who responded. I will make sure to get them ahead of time.

Make sure you allow enough time to get to the Sante Maria Delle Grazie.We kept getting lost. When we finally made it we were five minutes late and had to come back later that day (6 hours later).

We went last fall on a rainy night around 5:00 without reservations and we were 1) lucky to find the small church with some directional signs, and 2) someone didn't show for their reservations and we got in within 10 minutes. Best to have reservations and allow time to locate the church. Subway goes very near it with a short walk. Take map and look for signs. Since your're there, assume you will see the cathedral in Milan which is nearby.