Lock one's mouth and throw away the key

The photo shows the entrance of Cenacolo Vinciano in Milan, Italy. It's the place where you can see the world-famous mural art of The Last Supper by Leonardo da Vinci. The Last Supper was painted on a wall of a church named Santa Maria delle Grazie in late 15th century, and is still there. It is amazing, and it was amazing I could see The Last Supper with my own eyes. The Last Supper was so much huger than I expected before, and also right in front of the art, I felt like I was hearing a babble of the twelve disciples, and they seemed so real. You know the saying A picture is worth a thousand words, so I'll lock my mouth and throw away the key.