The Notre Dame Cathedral is a well-behaved church, with its brown exterior walls and smooth lines that seem uniquely smooth, but it is precisely because of this commonness that makes it stand out among the many bizarre churches in Italy. Another reason for Notre Dame's fame is that the famous painting by Da Vinci "Last Supper" hangs on the wall of Notre Dame's Cathedral of Gratitude, which attracts many painting enthusiasts. Notre Dame's Church of Gratitude is a complete architectural complex in Milan. It was built in 1492 by Brahman. His exquisite four corridors are also his works. Leonardo Da Vinci's masterpiece The Last Supper was painted on the wall of the monastery dining room next to the church. During World War II, the citizens of Milan protected the church wall with sandbags, which preserved the masterpiece. Over the centuries, many repairs were made, and flash photography was prohibited. Leonardo Da Vinci started writing in 1496 and finished the "Last Supper" in 1498. The painting is 4.97 metres wide. The figure in the painting is half that of the real person. It depicts the scene of Jesus having dinner with 12 disciples. The picture is full of rhythm and shows the artist's ability to depict the character's psychology. However, this is an oil painting rather than a traditional wet mural, which is very vulnerable to the erosion of the external environment, and has been repaired many times over the centuries, so that the face is totally different. In 1999, artists and scientists restored it on a large scale, restoring the original color, and removing the paint covered in the previous restoration, so as to restore its original appearance to the greatest extent.