Because the monks cannot support their monastery (in the north of Germany - filmed on the location of the beautiful monastery Chorin) anymore, they are forced out and have to join the only other monastery of their (fictional) order in Italy (with which they have a century old conflict, but that's not the story. The remaining monks, i.e. three, hit the road with hardly more that their robes. They all get tempted and distracted from their path, but finally all ends well. These temptations yield wonderful discourses on religion, a love story, and good view on life in general.
What makes the film so wonderful is the music. This order has specialized in choir singing. If you now think "Oh, I don't like choirs. That's not my film.", you still should give it a try. The music completes this wonderful film, is an integral part of the story, and is really moving. You will love it, regards of your usual musical preferences.
But may be you should see the film with a good sound system.